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.

Input: Consider Input: Passage: CBC Television stations can be received in many United States communities along the Canadian border over-the-air and have a significant audience in those areas. Such a phenomenon can also take place within Great Lakes communities such as Ashtabula, Ohio, which received programming from the CBC's London, Ontario, transmitter, based upon prevailing atmospheric conditions over Lake Erie. As of September 2010 CBC shut down its analogue transmitter and decided not to replace it with a digital transmitter. As a result, there is now a giant hole in the coverage of CBC in South-Western Ontario. Both CBC - Toronto and CBC - Windsor are both over 100 miles from London, ON and out of range for even the largest antennas[citation needed].

Output: What location in the United States has the highest viewership of CBC programming?

Input: Consider Input: Passage: Hoover began using wiretapping in the 1920s during Prohibition to arrest bootleggers. In the 1927 case Olmstead v. United States, in which a bootlegger was caught through telephone tapping, the United States Supreme Court ruled that FBI wiretaps did not violate the Fourth Amendment as unlawful search and seizure, as long as the FBI did not break into a person's home to complete the tapping. After Prohibition's repeal, Congress passed the Communications Act of 1934, which outlawed non-consensual phone tapping, but allowed bugging. In the 1939 case Nardone v. United States, the court ruled that due to the 1934 law, evidence the FBI obtained by phone tapping was inadmissible in court. After the 1967 case Katz v. United States overturned the 1927 case that had allowed bugging, Congress passed the Omnibus Crime Control Act, allowing public authorities to tap telephones during investigations as long as they obtain a warrant beforehand.

Output: When did Hoover stop using wiretapping?

Input: Consider Input: Passage: The Estonian dialects are divided into two groups the northern and southern dialects, historically associated with the cities of Tallinn in the north and Tartu in the south, in addition to a distinct kirderanniku dialect, that of the northeastern coast of Estonia.
Output: What city is north of Tallinn?