instruction:
In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.
question:
Passage: German Type IXD2 submarines were considerably larger than the original Type IXs. U-861 had a displacement of when at the surface and while submerged. The U-boat had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines plus two MWM RS34.5S six-cylinder four-stroke diesel engines for cruising, producing a total of for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to .
 Link Information: The range was extended to 31,500 nmi Answer: 7800
answer:
How much larger were the improved German submarines?


question:
Passage: John Wemyss was knighted in 1618 and created a Baronet of Nova Scotia in 1625. This included a charter to the barony of New Wemyss in that province of Canada. He was later advanced to the title of Earl of Wemyss and the patent was presented to him at Dunfermline personally by Charles I of England. John Wemyss was also a Privy Councillor, High Commissioner to the General Assembly of the Church of Scotland, and one of the Committee of the Estates. John Wemyss died in 1649 and was succeeded by his only son, David Wemyss, 2nd Earl of Wemyss. David Wemyss, the second earl spent a lifetime nurturing the resources of his estate, in particular his salt and coal mines. He also built a large harbour at Methil, Fife and greatly extended Wemyss Castle where he entertained Charles II of England in 1650 and 1651. He died in 1679 and was predeceased by his son so the estates fell to his daughter, Margaret Wemyss, 3rd Countess of Wemyss. Margaret married her cousin, James Wemyss, Lord Burntisland. Their son was David Wemyss, 4th Earl of Wemyss who succeeded his mother in 1705.
 Link Information: He died in 1679 Answer: 39
answer:
How old was Wemyss' son when he died in 1679?


question:
Passage: The Yardbirds are an English blues rock band from London. Formed in May 1963, the group originally included lead vocalist Keith Relf, lead guitarist Anthony "Top" Topham, rhythm guitarist Chris Dreja, bassist Paul Samwell-Smith and drummer Jim McCarty. In October, Topham was replaced by Eric Clapton. He remained until 13 March 1965, when he left due to creative disagreements. Clapton recommended Jimmy Page to replace him, but he declined and Jeff Beck took over. Page later joined on bass the following June, after Samwell-Smith abruptly quit; Dreja later took over the role, allowing Page to join Beck on guitar. This lineup was short-lived, however, as Beck left in November 1966. The group continued as a four-piece until July 1968, when Relf and McCarty left due to creative differences, primarily with Page. Dreja initially remained, but by August Page formed a new group with vocalist Robert Plant, bassist John Paul Jones and drummer John Bonham, who later renamed themselves Led Zeppelin.
 Link Information: who later renamed themselves Led Zeppelin. Answer: 1968
answer:

In what year did the Yardbirds rename themselves Led Zeppelin?