TASK DEFINITION: This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
PROBLEM: Passage: Old English was not static, and its usage covered a period of 700 years, from the Anglo-Saxon settlement of Britain in the 5th century to the late 11th century, some time after the Norman invasion. While indicating that the establishment of dates is an arbitrary process, Albert Baugh dates Old English from 450 to 1150, a period of full inflections, a synthetic language. Perhaps around 85 per cent of Old English words are no longer in use, but those that survived, to be sure, are basic elements of Modern English vocabulary.

SOLUTION: Where did Anglo-Saxons settle in the 500's?

PROBLEM: Passage: Harvard's faculty includes scholars such as biologist E. O. Wilson, cognitive scientist Steven Pinker, physicists Lisa Randall and Roy Glauber, chemists Elias Corey, Dudley R. Herschbach and George M. Whitesides, computer scientists Michael O. Rabin and Leslie Valiant, Shakespeare scholar Stephen Greenblatt, writer Louis Menand, critic Helen Vendler, historians Henry Louis Gates, Jr. and Niall Ferguson, economists Amartya Sen, N. Gregory Mankiw, Robert Barro, Stephen A. Marglin, Don M. Wilson III and Martin Feldstein, political philosophers Harvey Mansfield, Baroness Shirley Williams and Michael Sandel, Fields Medalist mathematician Shing-Tung Yau, political scientists Robert Putnam, Joseph Nye, and Stanley Hoffmann, scholar/composers Robert Levin and Bernard Rands, astrophysicist Alyssa A. Goodman, and legal scholars Alan Dershowitz and Lawrence Lessig.

SOLUTION: What scientist published "The Better Angels of Our Nature" in 2011?

PROBLEM: Passage: The only extant depiction of Edward's abbey, together with the adjacent Palace of Westminster, is in the Bayeux Tapestry. Some of the lower parts of the monastic dormitory, an extension of the South Transept, survive in the Norman undercroft of the Great School, including a door said to come from the previous Saxon abbey. Increased endowments supported a community increased from a dozen monks in Dunstan's original foundation, up to a maximum about eighty monks, although there was also a large community of lay brothers who supported the monastery's extensive property and activities.

SOLUTION:
Where is the only nonexistant depiction of Edward's abbey?