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.

[Q]: Passage: The first attempt to establish a proper governing body and adopted the current set of Rugby rules was the Foot Ball Association of Canada, organized on March 24, 1873 followed by the Canadian Rugby Football Union (CRFU) founded June 12, 1880, which included teams from Ontario and Quebec. Later both the Ontario and Quebec Rugby Football Union (ORFU and QRFU) were formed (January 1883), and then the Interprovincial (1907) and Western Interprovincial Football Union (1936) (IRFU and WIFU). The CRFU reorganized into an umbrella organization forming the Canadian Rugby Union (CRU) in 1891. The original forerunners to the current Canadian Football League, was established in 1956 when the IRFU and WIFU formed an umbrella organization, The Canadian Football Council (CFC). And then in 1958 the CFC left The CRFU to become The CFL.
[A]: The Canadian Rugby football Union was the first attempt at what?


[Q]: Passage: In the floor, just inside the great west door, in the centre of the nave, is the tomb of The Unknown Warrior, an unidentified British soldier killed on a European battlefield during the First World War. He was buried in the abbey on 11 November 1920. This grave is the only one in the abbey on which it is forbidden to walk.[citation needed]
[A]: When was The Known Warrior buried?


[Q]: Passage: The gas centrifuge process, where gaseous uranium hexafluoride (UF
6) is separated by the difference in molecular weight between 235UF6 and 238UF6 using high-speed centrifuges, is the cheapest and leading enrichment process. The gaseous diffusion process had been the leading method for enrichment and was used in the Manhattan Project. In this process, uranium hexafluoride is repeatedly diffused through a silver-zinc membrane, and the different isotopes of uranium are separated by diffusion rate (since uranium 238 is heavier it diffuses slightly slower than uranium-235). The molecular laser isotope separation method employs a laser beam of precise energy to sever the bond between uranium-235 and fluorine. This leaves uranium-238 bonded to fluorine and allows uranium-235 metal to precipitate from the solution. An alternative laser method of enrichment is known as atomic vapor laser isotope separation (AVLIS) and employs visible tunable lasers such as dye lasers. Another method used is liquid thermal diffusion.
[A]:
What is the name of the least widely used enrichment process?