question: Who is the paternal grandfather of Peter Grubb Jr.?
context: [["Abd al-Muttalib", ["Abd al- Muttalib Shaybah ibn Hashim( c. 497 \u2013 578) was the grandfather of Islamic prophet Muhammad."]], ["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."]], ["Lyon Cohen", ["Lyon Cohen( 1868\u20131937) was a Polish- born Canadian businessman and a philanthropist.", "He was the grandfather of singer/ poet Leonard Cohen."]], ["Henry Krause", ["Henry J.\" Red\" Krause, Jr.( August 28, 1913 \u2013 February 20, 1987) was an American football offensive lineman in the National Football League for the Brooklyn Dodgers and the Washington Redskins.", "He played college football at St. Louis University.", "He is the grandfather of Jennifer Krause", "He is the great grandfather of Payton Hoeing"]], ["John Westley", ["Rev. John Westley( 1636 \u2013 78) was an English nonconformist minister.", "He was the grandfather of John Wesley( founder of Methodism)."]], ["Henry Bates Grubb", ["Henry Bates Grubb( February 6, 1774 \u2013 March 9, 1823) was a third- generation member of the Grubb Family Iron Dynasty, the founder of the family's enterprises headquartered at Mount Hope near Lancaster, Pennsylvania, and perhaps the family's first\" true\" ironmaster.", "He was the son and heir of Peter Grubb, Jr. who, with his brother Curtis, had owned and operated the Cornwall ironworks founded by their father Peter Grubb in 1737.", "Henry and his heirs rebuilt the family business after most of the original Peter Grubb holdings were gradually acquired by Robert Coleman between 1783 and 1802.", "The Grubbs and Colemans were among the largest iron producers in Pennsylvania through the mid-19th century."]], ["Fred Le Deux", ["Frederick\" Fred\" Le Deux( born 4 December 1934) was an Australian rules footballer who played with Geelong in the Victorian Football League( VFL).", "He is the grandfather of Tom Hawkins."]], ["Peter Grubb (mason)", ["The youngest of the seven sons of John Grubb and his wife Frances of Brandywine Hundred, Peter first learned the stonemasonry trade.", "In 1729, he built a water corn and boulting mill in Bradford, Pennsylvania.", "He constructed his first iron bloomery (a crude form of furnace) in 1737 at Furnace Creek, on the modern border of Lancaster and Lebanon counties.", "Grubb constructed a regular iron furnace, known as Hopewell on Hammer Creek near his bloomery.", "As he started to operate Hopewell, Peter soon located three mountains of magnetic iron ore just west of the furnace.", "He decided to mine the ore and by 1739 had acquired over that he called Cornwall Iron Mines, in honor of his father's birthplace.", "In 1742, he opened Cornwall Iron Furnace to take advantage of the discovery.", "Peter Grubb's Hopewell Forge Mansion, completed around 1740 and later occupied by his son Peter Jr., still stands about six miles (10 km) from Cornwall on present-day Route 322.", "In 1745 Peter decided to relinquish direct control of the ironworks, and he leased the operation to Cury and Company for 20 years at \u00a3250 a year.", "He moved with his wife to Wilmington, Delaware, where he engaged in the buying and selling of real estate and lived out his life."]], ["Peter Grubb Jr.", ["Peter Grubb Jr. (1740\u20131786), Patriot and second son of Peter and Martha Bates Grubb, was a second-generation member of the Grubb Family Iron Dynasty along with his older brother Curtis Grubb.", "They operated the Cornwall Ironworks, making significant contributions to the American Revolutionary War effort.", "The brothers inherited the ironworks from their father in 1754, with Peter, as the youngest, receiving only a one-third interest.", "They took over operation of the ironworks about 1765 and expanded it successfully.", "Peter, who had more ironmaking experience, took over the nearby Hopewell Forges, making bar iron from pig iron produced by Curtis at Cornwall Furnace.", "They operated the business through and after the Revolution, becoming quite prosperous until they died, Peter in 1786 and Curtis in 1789.", "Most of the Cornwall Ironworks fell out of family hands during the period 1783 - 1802, to Robert Coleman who became Pennsylvania's first millionaire.", "But a portion remained with Peter Jr.'s heirs, who added to it to become major Pennsylvania producers of iron in the mid-19th century, operating out of Mount Hope Estate."]], ["Zhao Shoushan", ["Zhao Shoushan( 12 November 1894 \u2013 20 June 1965) was a KMT general and later Chinese Communist Party politician.", "He is the grandfather of Zhao Leji."]]]
supporting_facts: [["Peter Grubb Jr.", 0], ["Peter Grubb (mason)", 0]]
evidences: [["Peter Grubb Jr.", "father", "Peter"], ["Peter Grubb", "father", "John Grubb"]]
answer: John Grubb