question: Who is the maternal grandfather of Claudia Antonia?
context: [["Claudia Antonia", ["Claudia Antonia (Classical Latin:)", "(c. AD 30\u2013AD 66) was the daughter and oldest surviving child of the Roman Emperor Claudius and the only child of his second wife Aelia Paetina.", "Antonia was a great great-niece of the Emperor Augustus, great-niece of the Emperor Tiberius, first cousin of the Emperor Caligula, half-sister to Claudia Octavia and Britannicus (her father's children by his third marriage to Valeria Messalina), and cousin, stepsister and sister-in-law of the Emperor Nero."]], ["Fujiwara no Nagara", [", also known as Fujiwara no Nagayoshi, was a Japanese statesman, courtier and politician of the early Heian period.", "He was the grandfather of Emperor Y\u014dzei."]], ["Guillaume Wittouck", ["Guillaume Wittouck( 1749- 1829) was a Belgian lawyer and High Magistrate.", "He was the Grandfather of industrialist Paul Wittouck."]], ["Lyon Cohen", ["Lyon Cohen( 1868\u20131937) was a Polish- born Canadian businessman and a philanthropist.", "He was the grandfather of singer/ poet Leonard Cohen."]], ["Prithvipati Shah", ["Prithvipati Shah( ?\u20131716) was the king of the Gorkha Kingdom in the Indian subcontinent, present- day Nepal.", "He was the grandfather of Nara Bhupal Shah."]], ["Kaya Alp", ["Kaya Alp was, according to Ottoman tradition, the son of K\u0131z\u0131l Bu\u011fa and the father of Suleyman Shah, who was, in turn, the grandfather of Ertu\u011frul, and the great grandfather of the Ottoman Empire founder, Osman I."]], ["Aelia Paetina", ["Aelia Paetina or Paetina (fl.", "early 1st century AD) was the second wife of the Roman Emperor Claudius.", "Her biological father was a consul of 4 AD, Sextus Aelius Catus, while her mother is unknown."]], ["John Westley", ["Rev. John Westley( 1636 \u2013 78) was an English nonconformist minister.", "He was the grandfather of John Wesley( founder of Methodism)."]], ["Henry Bryant (naturalist)", ["Henry Bryant( May 12, 1820 \u2013 February 2, 1867) was an American physician and naturalist.", "He was the grandfather of Henry Bryant Bigelow."]], ["Abd al-Muttalib", ["Abd al- Muttalib Shaybah ibn Hashim( c. 497 \u2013 578) was the grandfather of Islamic prophet Muhammad."]]]
supporting_facts: [["Claudia Antonia", 1], ["Aelia Paetina", 2]]
evidences: [["Claudia Antonia", "mother", "Aelia Paetina"], ["Aelia Paetina", "father", "Sextus Aelius Catus"]]
answer: Sextus Aelius Catus