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.

Example Input: Passage: The FBI has maintained files on numerous people, including celebrities such as Elvis Presley, Frank Sinatra, John Denver, John Lennon, Jane Fonda, Groucho Marx, Charlie Chaplin, the band MC5, Lou Costello, Sonny Bono, Bob Dylan, Michael Jackson, and Mickey Mantle. The files were collected for various reasons. Some of the subjects were investigated for alleged ties to the Communist party (Charlie Chaplin and Groucho Marx), or in connection with antiwar activities during the Vietnam War (John Denver, John Lennon, and Jane Fonda). Numerous celebrity files concern threats or extortion attempts against them (Sonny Bono, John Denver, John Lennon, Elvis Presley, Michael Jackson, Mickey Mantle, Groucho Marx, and Frank Sinatra).
Example Output: Who has the FBI never maintained a file on?

Example Input: Passage: During the Middle Ages, Thuringia was situated at the border between Germanic and Slavic territories, marked by the Saale river. The Ostsiedlung movement led to the assimilation of Slavic people between the 11th and the 13th century under German rule. The population growth increased during the 18th century and stayed high until World War I, before it slowed within the 20th century and changed to a decline since 1990. Since the beginning of Urbanisation around 1840, the Thuringian cities have higher growth rates resp. smaller rates of decline than rural areas (many villages lost half of their population since 1950, whereas the biggest cities (Erfurt and Jena) keep growing).
Example Output: Where was Thuringia attacking in the Middle Ages?

Example Input: Passage: The location on the banks of the river Rhine allowed Utrecht to become an important trade centre in the Northern Netherlands. The growing town Utrecht was granted city rights by Henry V in 1122. When the main flow of the Rhine moved south, the old bed, which still flowed through the heart of the town became evermore canalized; and the wharf system was built as an inner city harbour system. On the wharfs storage facilities (werfkelders) were built, on top of which the main street, including houses was constructed. The wharfs and the cellars are accessible from a platform at water level with stairs descending from the street level to form a unique structure.[nb 2] The relations between the bishop, who controlled many lands outside of the city, and the citizens of Utrecht was not always easy. The bishop, for example dammed the Kromme Rijn at Wijk bij Duurstede to protect his estates from flooding. This threatened shipping for the city and led the city of Utrecht to commission a canal to ensure access to the town for shipping trade: the Vaartse Rijn, connecting Utrecht to the Hollandse IJssel at IJsselstein.
Example Output:
What allowed Utrecht to become a major global trading center?