Use a disfluent question or a proper question and find the answer to the question based on the given context or return None if an answer can't be found. A disfluent question is a question that has some interruptions in it while framing. A proper question is the correct form of the question without any disfluency.

Example input: proper question: In what year did the U of C become one of 7 founding members of the Association of Chicago Universities? 
 disfluent question: In what year did Robert Harper or did the U of C become one of 7 founding members of the Association of Chicago Universities? 
 context: Founded by the American Baptist Education Society with a donation from oil magnate and wealthiest man in history John D. Rockefeller, the University of Chicago was incorporated in 1890; William Rainey Harper became the university's first president in 1891, and the first classes were held in 1892. Both Harper and future president Robert Maynard Hutchins advocated for Chicago's curriculum to be based upon theoretical and perennial issues rather than on applied sciences and commercial utility. With Harper's vision in mind, the University of Chicago also became one of the 14 founding members of the Association of American Universities, an international organization of leading research universities, in 1900.
Example output: None
Example explanation: The answer to the above question is not found from the context hence it is not answerable so the output is 'None' so it is a positive example.
Q: proper question: What exposed the former coasts of Europe? 
 disfluent question: What warmed up from 22,000 years ago rather exposed the former coasts of Europe? 
 context: As northwest Europe slowly began to warm up from 22,000 years ago onward, frozen subsoil and expanded alpine glaciers began to thaw and fall-winter snow covers melted in spring. Much of the discharge was routed to the Rhine and its downstream extension. Rapid warming and changes of vegetation, to open forest, began about 13,000 BP. By 9000 BP, Europe was fully forested. With globally shrinking ice-cover, ocean water levels rose and the English Channel and North Sea re-inundated. Meltwater, adding to the ocean and land subsidence, drowned the former coasts of Europe transgressionally.
A:
None