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: The thalidomide tragedy resurrected Kefauver's bill to enhance drug regulation that had stalled in Congress, and the Kefauver-Harris Amendment became law on 10 October 1962. Manufacturers henceforth had to prove to FDA that their drugs were effective as well as safe before they could go on the US market. The FDA received authority to regulate advertising of prescription drugs and to establish good manufacturing practices. The law required that all drugs introduced between 1938 and 1962 had to be effective. An FDA - National Academy of Sciences collaborative study showed that nearly 40 percent of these products were not effective. A similarly comprehensive study of over-the-counter products began ten years later.

SOLUTION: When did the FDA Amendment become a law?

PROBLEM: Passage: In May 2007, YouTube launched its Partner Program, a system based on AdSense which allows the uploader of the video to share the revenue produced by advertising on the site. YouTube typically takes 45 percent of the advertising revenue from videos in the Partner Program, with 55 percent going to the uploader. There are over a million members of the YouTube Partner Program. According to TubeMogul, in 2013 a pre-roll advertisement on YouTube (one that is shown before the video starts) cost advertisers on average $7.60 per 1000 views. Usually no more than half of eligible videos have a pre-roll advertisement, due to a lack of interested advertisers. Assuming pre-roll advertisements on half of videos, a YouTube partner would earn 0.5 X $7.60 X 55% = $2.09 per 1000 views in 2013.

SOLUTION: What did YouTube launch in May 2013?

PROBLEM: Passage: Large masses, such as ice sheets or glaciers, can depress the crust of the Earth into the mantle. The depression usually totals a third of the ice sheet or glacier's thickness. After the ice sheet or glacier melts, the mantle begins to flow back to its original position, pushing the crust back up. This post-glacial rebound, which proceeds very slowly after the melting of the ice sheet or glacier, is currently occurring in measurable amounts in Scandinavia and the Great Lakes region of North America.

SOLUTION:
Where has post-glacial rebound stopped occuring?