TASK DEFINITION: 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.
PROBLEM: Passage: Notably, the most broadly influential innovation of 20th-century American tort law was the rule of strict liability for defective products, which originated with judicial glosses on the law of warranty. In 1963, Roger J. Traynor of the Supreme Court of California threw away legal fictions based on warranties and imposed strict liability for defective products as a matter of public policy in the landmark case of Greenman v. Yuba Power Products. The American Law Institute subsequently adopted a slightly different version of the Greenman rule in Section 402A of the Restatement (Second) of Torts, which was published in 1964 and was very influential throughout the United States. Outside the U.S., the rule was adopted by the European Economic Community in the Product Liability Directive of July 1985 by Australia in July 1992 and by Japan in June 1994.

SOLUTION: What case occurred in 1994?

PROBLEM: Passage: According to figures from Britain's Radio Manufacturers Association, 18,999 television sets had been manufactured from 1936 to September 1939, when production was halted by the war.

SOLUTION: How many television sets had been manufactured by 1939?

PROBLEM: Passage: Serbo-Croatian was standardized in the mid-19th-century Vienna Literary Agreement by Croatian and Serbian writers and philologists, decades before a Yugoslav state was established. From the very beginning, there were slightly different literary Serbian and Croatian standards, although both were based on the same Shtokavian subdialect, Eastern Herzegovinian. In the 20th century, Serbo-Croatian served as the official language of the Kingdom of Yugoslavia (when it was called "Serbo-Croato-Slovenian"), and later as one of the official languages of the Socialist Federal Republic of Yugoslavia. The breakup of Yugoslavia affected language attitudes, so that social conceptions of the language separated on ethnic and political lines. Since the breakup of Yugoslavia, Bosnian has likewise been established as an official standard in Bosnia and Herzegovina, and there is an ongoing movement to codify a separate Montenegrin standard. Serbo-Croatian thus generally goes by the ethnic names Serbian, Croatian, Bosnian, and sometimes Montenegrin and Bunjevac.

SOLUTION:
In what year was a Yugoslav state standardized?