Definition: 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: Passage: The army employs various individual weapons to provide light firepower at short ranges. The most common weapons used by the army are the compact variant of the M16 rifle, the M4 carbine, as well as the 7.6251mm variant of the FN SCAR for Army Rangers. The primary sidearm in the U.S. Army is the 9 mm M9 pistol; the M11 pistol is also used. Both handguns are to be replaced through the Modular Handgun System program. Soldiers are also equiped with various hand grenades, such as the M67 fragmentation grenade and M18 smoke grenade.
Output:
What is the primary sidearm used by the Coast Guard?