question: Who is Mohammed Bin Khalifa Bin Zayed Al Nahyan's paternal grandfather?
context: [["Hazza bin Zayed bin Sultan Al Nahyan", ["Sheikh Hazza bin Zayed Al Nahyan is the United Arab Emirates Head of State for National Security Advisor."]], ["Nasser bin Zayed Al Nahyan", ["Nasser bin Zayed Al Nahyan( died 2 June 2008) was an Emirati royal and a member of the Al Nahyan family."]], ["Khalifa bin Zayed bin Khalifa Al Nahyan", ["Sheikh Khalifa bin Zayed bin Khalifa Al Nahyan was the eldest son of Abu Dhabi ruler Zayed bin Khalifa Al Nahyan.", "He was brother of 4 Abu Dhabi rulers Tahnoon, Hamdan, Saqr and Sultan bin Zayed bin Khalifa Al Nahyan( who was the grandfather of current Ruler Khalifa bin Zayed bin Sultan Al Nahyan).", "He was a great grandfather of Nahyan Bin Mubarik Bin Muhammad Bin Khalifa.", "He refused to ascend the throne as his mother begged him to refuse, as she was sure he would be killed.", "He reportedly built Al- Muwaiji Fort in what is now the city of Al Ain during the early 20th century, during the reign of his father."]], ["Sultan bin Zayed bin Khalifa Al Nahyan", ["Sheikh Sultan bin Zayed bin Khalifa Al Nahyan was the grandfather of current Ruler Khalifa bin Zayed Al Nahyan and father of previous ruler Zayed bin Sultan Al Nahyan.", "He killed his brother Hamdan in 1922 to rule Abu Dhabi, but was himself toppled and killed by another brother Saqr in 1926."]], ["Issa bin Zayed Al Nahyan", ["Issa bin Zayed Al Nahyan is the son of former United Arab Emirates President Zayed bin Sultan Al Nahyan; the half brother of the present ruler of Abu Dhabi, the President Khalifa bin Zayed Al Nahyan; and the half brother of Crown Prince Mohammed bin Zayed Al Nahyan.", "Although a member of the royal family and apart from being a prominent real estate developer in the UAE, being the owner of Al Hekma Tower in Dubai, Issa bin Zayed holds no official or political position within the government of the United Arab Emirates.", "In April 2009 Issa bin Zayed was subject to a controversy in which a video tape of torture smuggled out of the United Arab Emirates to the United States by two Palestinian brothers, who were his business associates, showed Issa mercilessly torturing a man with whips, electric cattle prods, and wooden planks with protruding nails and running him over repeatedly with an SUV.", "Issa bin Zayed was initially put under arrest with the UAE government stating that matters were resolved\" privately\".", "One of the Palestinian brothers, Nabulsi, claimed Issa bin Zayed breached his contract and subjected him to torture, emotional distress, and malicious prosecution and demanded$ 80 million in repatriation.", "Emirati court found Issa not guilty on the principle of diminished responsibility and instead condemned and sentenced the two brothers for using the video as blackmail and extortion.", "The court was accused, by international human rights observers, of having failed to deliver justice."]], ["Falah bin Zayed Al Nahyan", ["Sheikh Falah bin Zayed bin Sultan bin Zayed bin Khalifa Al Nahyan( born 7 November 1970) is a member of Al Nahyan the ruling royal family of Abu Dhabi.", "He is the son of Zayed bin Sultan Al Nahyan, the founder, first president of United Arab Emirates and emir of Abu Dhabi.", "He is the half brother of Sheikh Khalifa bin Zayed Al Nahyan, the current President of the United Arab Emirates.", "He is also half brother of Sheikh Mohammed bin Zayed Al Nahyan, Crown Prince of Abu Dhabi and Deputy Supreme Commander of the U.A.E Armed Forces.", "He was the captain of a national team."]], ["Mohammed bin Khalifa bin Zayed Al Nahyan", ["Mohammed bin Khalifa bin Zayed Al Nahyan  is a Emirati royal politician.", "He is the son of current Emir of Abu Dhabi emirate and President of the United Arab Emirates, Khalifa bin Zayed Al Nahyan.", "Sheikh Mohammed is the member of Executive Council of Abu Dhabi (the cabinet of Abu Dhabi).", "He is also on the board of directors of Abu Dhabi Investment Authority", "(Abu Dhabi's sovereign wealth fund), under the chairman, his father.", "In 2009, he was appointed chairman of Abu Dhabi Retirement Pensions and Benefits Fund.", "He is the chairman of Abu Dhabi department of finance while acting chairman is Hamad Al Hurr Al Suwaidi."]], ["Ahmed Abdul Khaleq", ["Ahmed Abdul Khaleq( born c. 1977) is a blogger and activist of the stateless Bedoun minority who formerly resided in Ajman in the United Arab Emirates.", "From April to November 2011, he was imprisoned as one of the UAE Five on charges of insulting United Arab Emirates President Khalifa bin Zayed Al Nahyan, Vice President Mohammed bin Rashid Al Maktoum, and Crown Prince of Abu Dhabi Mohammed bin Zayed Al Nahyan.", "Amnesty International designated him a prisoner of conscience, and he was released following a presidential pardon.", "In May 2012, he was rearrested and given a choice between indefinite detention or exile.", "On 16 July, he left the country for Thailand."]], ["Khalifa bin Zayed Al Nahyan", ["Khalifa bin Zayed bin Sultan Al Nahyan (born 7 September 1948; referred to as Sheikh Khalifa) is the current President of the United Arab Emirates, the Emir of Abu Dhabi, the Supreme Commander of the Union Defence Force and the chairman of the Supreme Petroleum Council.", "Sheikh Khalifa is also chairman of Abu Dhabi Investment Authority, which manages $875 billion in assets, the largest amount managed by a nation's head of state in the world.", "Collectively, the Al Nahyan family is believed to hold a fortune of $150 billion.", "Sheikh Khalifa succeeded his father, Zayed bin Sultan Al Nahyan, as Emir of Abu Dhabi on 2 November 2004 and became the President of the UAE the next day.", "As Crown Prince, he had already de facto carried out some aspects of the presidency since the late 1990s while his father was facing health problems.", "In January 2014, Khalifa suffered a stroke but was in a stable condition.", "He has since assumed a lower profile in state affairs, but retained presidential powers.", "His half brother Sheikh Mohammed bin Zayed Al Nahyan now carries out public affairs of the state and day-to-day decision-making of the Emirate of Abu Dhabi."]], ["Ahmed Mansoor", ["Ahmed Mansoor Al Shehhi is an Emirati activist who was arrested as one of the UAE Five in April 2011 on charges of breaking United Arab Emirates law of defamation by insulting heads of state, namely UAE president Khalifa bin Zayed Al Nahyan, vice president Mohammed bin Rashid Al Maktoum, and Abu Dhabi crown prince Mohammed bin Zayed Al Nahyan through running an anti-government website that express anti-government views.", "He was pardoned by UAE's president Sheikh Khalifa bin Zayed.", "In 2015, Mansoor received the Martin Ennals Award for Human Rights Defenders.", "Mansoor was arrested again in March 2017 on charges of using social media platforms to threaten public order and publish false and misleading information.", "He was found guilty and convicted for threatening state security and given a prison sentence of 10 years."]]]
supporting_facts: [["Mohammed bin Khalifa bin Zayed Al Nahyan", 1], ["Khalifa bin Zayed Al Nahyan", 3]]
evidences: [["Mohammed bin Khalifa bin Zayed Al Nahyan", "father", "Khalifa bin Zayed Al Nahyan"], ["Khalifa bin Zayed Al Nahyan", "father", "Zayed bin Sultan Al Nahyan"]]
answer: Zayed bin Sultan Al Nahyan