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: Planetary geologists have measured different abundances of oxygen isotopes in samples from the Earth, the Moon, Mars, and meteorites, but were long unable to obtain reference values for the isotope ratios in the Sun, believed to be the same as those of the primordial solar nebula. Analysis of a silicon wafer exposed to the solar wind in space and returned by the crashed Genesis spacecraft has shown that the Sun has a higher proportion of oxygen-16 than does the Earth. The measurement implies that an unknown process depleted oxygen-16 from the Sun's disk of protoplanetary material prior to the coalescence of dust grains that formed the Earth.
Example Output: Where have Genesis geologists measured oxygen isotopes?

Example Input: Passage: The islands were occupied by a garrison of British Marines and a civilian population was gradually built up. Whalers also set up on the islands as a base for operations in the Southern Atlantic. However, the opening of the Suez Canal in 1869, together with the gradual move from sailing ships to coal-fired steam ships, increased the isolation of the islands, as they were no longer needed as a stopping port or for shelter for journeys from Europe to East Asia.
Example Output: By who was the sailing ships occupied?

Example Input: Passage: The current US fleet of Nimitz-class carriers will be followed into service (and in some cases replaced) by the ten-ship Gerald R. Ford class. It is expected that the ships will be more automated in an effort to reduce the amount of funding required to staff, maintain and operate its supercarriers. The main new features are implementation of Electromagnetic Aircraft Launch System (EMALS) (which replace the old steam catapults) and unmanned aerial vehicles. With the deactivation of USS Enterprise in December 2012 (decommissioning scheduled for 2016), the U.S. fleet comprises 10 active supercarriers. On 24 July 2007, the House Armed Services Seapower subcommittee recommended seven or eight new carriers (one every four years). However, the debate has deepened over budgeting for the $12–14.5 billion (plus $12 billion for development and research) for the 100,000 ton Gerald R. Ford-class carrier (estimated service 2016) compared to the smaller $2 billion 45,000 ton America-class amphibious assault ships able to deploy squadrons of F-35B of which one is already active, another is under construction and nine more are planned.
Example Output:
What will some of the current UN fleet of Nimitz-class carriers be replaced with?