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: Consider Input: Passage: The Gregorian calendar is a solar calendar. A regular Gregorian year consists of 365 days, but as in the Julian calendar, in a leap year, a leap day is added to February. In the Julian calendar a leap year occurs every 4 years, but the Gregorian calendar omits 3 leap days every 400 years. In the Julian calendar, this leap day was inserted by doubling 24 February, and the Gregorian reform did not change the date of the leap day. In the modern period, it has become customary to number the days from the beginning of the month, and February 29th is often considered as the leap day. Some churches, notably the Roman Catholic Church, delay February festivals after the 23rd by one day in leap years.

Output: What calendar is a lunar calendar?

Input: Consider Input: Passage: The average Mongol garrison family of the Yuan dynasty seems to have lived a life of decaying rural leisure, with income from the harvests of their Chinese tenants eaten up by costs of equipping and dispatching men for their tours of duty. The Mongols practiced debt slavery, and by 1290 in all parts of the Mongol Empire commoners were selling their children into slavery. Seeing this as damaging to the Mongol nation, Kublai in 1291 forbade the sale abroad of Mongols. Kublai wished to persuade the Chinese that he was becoming increasingly sinicized while maintaining his Mongolian credentials with his own people. He set up a civilian administration to rule, built a capital within China, supported Chinese religions and culture, and devised suitable economic and political institutions for the court. But at the same time he never abandoned his Mongolian heritage.

Output: By what year was selling children into slavery uncommon among the Mongols?

Input: Consider Input: Passage: In some societies, clothing may be used to indicate rank or status. In ancient Rome, for example, only senators could wear garments dyed with Tyrian purple. In traditional Hawaiian society, only high-ranking chiefs could wear feather cloaks and palaoa, or carved whale teeth. Under the Travancore Kingdom of Kerala, (India), lower caste women had to pay a tax for the right to cover their upper body. In China, before establishment of the republic, only the emperor could wear yellow. History provides many examples of elaborate sumptuary laws that regulated what people could wear. In societies without such laws, which includes most modern societies, social status is instead signaled by the purchase of rare or luxury items that are limited by cost to those with wealth or status. In addition, peer pressure influences clothing choice.
Output: Who is not allowed to wear garments dyed purple in ancient Rome