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: On 14 September 2009, U.S. Special Forces killed two men and wounded and captured two others near the Somali village of Baarawe. Witnesses claim that helicopters used for the operation launched from French-flagged warships, but that could not be confirmed. A Somali-based al-Qaida affiliated group, the Al-Shabaab, has confirmed the death of "sheik commander" Saleh Ali Saleh Nabhan along with an unspecified number of militants. Nabhan, a Kenyan, was wanted in connection with the 2002 Mombasa attacks.
Output:
What did U.S. Special Forces do on 14 September 2002?