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: Conventional ("tailhook") aircraft rely upon a landing signal officer (LSO, radio call sign paddles) to monitor the aircraft's approach, visually gauge glideslope, attitude, and airspeed, and transmit that data to the pilot. Before the angled deck emerged in the 1950s, LSOs used colored paddles to signal corrections to the pilot (hence the nickname). From the late 1950s onward, visual landing aids such as Optical Landing System have provided information on proper glide slope, but LSOs still transmit voice calls to approaching pilots by radio.
Example Output: What does OSL stand for?

Example Input: Passage: Contrary to the diffusionist theory, it appears that there was simultaneously a structural evolution towards the pointed arch, for the purpose of vaulting spaces of irregular plan, or to bring transverse vaults to the same height as diagonal vaults. This latter occurs at Durham Cathedral in the nave aisles in 1093. Pointed arches also occur extensively in Romanesque decorative blind arcading, where semi-circular arches overlap each other in a simple decorative pattern, and the points are accidental to the design.
Example Output: Which cathedral is the twisted arch used to match the heights of transverse and diagonal vaults?

Example Input: Passage: Elizabeth's many historic visits and meetings include a state visit to the Republic of Ireland and reciprocal visits to and from the Pope. She has seen major constitutional changes, such as devolution in the United Kingdom, Canadian patriation, and the decolonisation of Africa. She has also reigned through various wars and conflicts involving many of her realms. She is the world's oldest reigning monarch as well as Britain's longest-lived. In 2015, she surpassed the reign of her great-great-grandmother, Queen Victoria, to become the longest-reigning British head of state and the longest-reigning queen regnant in world history.
Example Output:
What was the last year that Elizabeth did a state visit in the Republic of Ireland?