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: 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 solution: 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.

Problem: proper question: At Millingen aan de Rijn where the Rhine splits, what does it change it's name to? 
 disfluent question: At Millingen aan de Rijn where the Waal no Rhine splits, what does it change it's name to? 
 context: The shape of the Rhine delta is determined by two bifurcations: first, at Millingen aan de Rijn, the Rhine splits into Waal and Pannerdens Kanaal, which changes its name to Nederrijn at Angeren, and second near Arnhem, the IJssel branches off from the Nederrijn. This creates three main flows, two of which change names rather often. The largest and southern main branch begins as Waal and continues as Boven Merwede (upper Merwede), Beneden Merwede (Lower Merwede), Noord River (North River), Nieuwe Maas (New Meuse), Het Scheur (the Rip) and Nieuwe Waterweg (New Waterway). The middle flow begins as Nederrijn, then changes into Lek, then joins the Noord, thereby forming Nieuwe Maas. The northern flow keeps the name IJssel until it flows into Lake IJsselmeer. Three more flows carry significant amounts of water: the Nieuwe Merwede (New Merwede), which branches off from the southern branch where it changes from Boven to Beneden Merwede; the Oude Maas (Old Meuse), which branches off from the southern branch where it changes from Beneden Merwede into Noord, and Dordtse Kil, which branches off from Oude Maas.

Solution: Nederrijn at Angeren