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 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.
[A]: By what year was selling children into slavery uncommon among the Mongols?

[Q]: Passage: The law of criminal procedure in the United States consists of a massive overlay of federal constitutional case law interwoven with the federal and state statutes that actually provide the foundation for the creation and operation of law enforcement agencies and prison systems as well as the proceedings in criminal trials. Due to the perennial inability of legislatures in the U.S. to enact statutes that would actually force law enforcement officers to respect the constitutional rights of criminal suspects and convicts, the federal judiciary gradually developed the exclusionary rule as a method to enforce such rights. In turn, the exclusionary rule spawned a family of judge-made remedies for the abuse of law enforcement powers, of which the most famous is the Miranda warning. The writ of habeas corpus is often used by suspects and convicts to challenge their detention, while the Civil Rights Act of 1871 and Bivens actions are used by suspects to recover tort damages for police brutality.
[A]: What have US legislatures been able to enact successfully?

[Q]: Passage: Albert spent the first six months of 1913 on the training ship HMS Cumberland in the West Indies and on the east coast of Canada. He was rated as a midshipman aboard HMS Collingwood on 15 September 1913, and spent three months in the Mediterranean. His fellow officers gave him the nickname "Mr. Johnson". One year after his commission, he began service in the First World War. He was mentioned in despatches for his action as a turret officer aboard Collingwood in the Battle of Jutland (31 May 1 June 1916), an indecisive engagement with the German navy that was the largest naval action of the war. He did not see further combat, largely because of ill health caused by a duodenal ulcer, for which he had an operation in November 1917.
[A]:
In what year did Albert leave the military?