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 logical format of an audio CD (officially Compact Disc Digital Audio or CD-DA) is described in a document produced in 1980 by the format's joint creators, Sony and Philips. The document is known colloquially as the Red Book CD-DA after the colour of its cover. The format is a two-channel 16-bit PCM encoding at a 44.1 kHz sampling rate per channel. Four-channel sound was to be an allowable option within the Red Book format, but has never been implemented. Monaural audio has no existing standard on a Red Book CD; thus, mono source material is usually presented as two identical channels in a standard Red Book stereo track (i.e., mirrored mono); an MP3 CD, however, can have audio file formats with mono sound.
Example Output: What was the sampling rate for the four-channel sound?

Example Input: Passage: The U.S. Army currently consists of 10 active divisions as well as several independent units. The force is in the process of contracting after several years of growth. In June 2013, the Army announced plans to downsize to 32 active combat brigade teams by 2015 to match a reduction in active duty strength to 490,000 soldiers. Army Chief of Staff Raymond Odierno has projected that by 2018 the Army will eventually shrink to "450,000 in the active component, 335,000 in the National Guard and 195,000 in U.S. Army Reserve."
Example Output: How many divisions are there in the U.S. Navy?

Example Input: Passage: The basic equipment or kit players are required to wear includes a shirt, shorts, socks, footwear and adequate shin guards. An athletic supporter and protective cup is highly recommended for male players by medical experts and professionals. Headgear is not a required piece of basic equipment, but players today may choose to wear it to protect themselves from head injury. Players are forbidden to wear or use anything that is dangerous to themselves or another player, such as jewellery or watches. The goalkeeper must wear clothing that is easily distinguishable from that worn by the other players and the match officials.
Example Output:
What is the equipment a player wears never called?