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: Rail transport in Victoria is provided by several private and public railway operators who operate over government-owned lines. Major operators include: Metro Trains Melbourne which runs an extensive, electrified, passenger system throughout Melbourne and suburbs; V/Line which is now owned by the Victorian Government, operates a concentrated service to major regional centres, as well as long distance services on other lines; Pacific National, CFCL Australia which operate freight services; Great Southern Rail which operates The Overland MelbourneAdelaide; and NSW TrainLink which operates XPTs MelbourneSydney.

SOLUTION: Who owns the rail cars in Victoria?

PROBLEM: Passage: As a uniformed military service, the Army is part of the Department of the Army, which is one of the three military departments of the Department of Defense. The U.S. Army is headed by a civilian senior appointed civil servant, the Secretary of the Army (SECARMY), and by a chief military officer, the Chief of Staff of the Army (CSA) who is also a member of the Joint Chiefs of Staff. In the fiscal year 2016, the projected end strength for the Regular Army (USA) was 475,000 soldiers; the Army National Guard (ARNG) had 342,000 soldiers, and the United States Army Reserve (USAR) had 198,000 soldiers; the combined-component strength of the U.S. Army was 1,015,000 soldiers. As a branch of the armed forces, the mission of the U.S. Army is "to fight and win our Nation's wars, by providing prompt, sustained, land dominance, across the full range of military operations and the spectrum of conflict, in support of combatant commanders." The service participates in conflicts worldwide and is the major ground-based offensive and defensive force.

SOLUTION: How many military departments does the Department of Agriculture have?

PROBLEM: Passage: Alexandria was the most important trade center in the whole empire during Athanasius's boyhood. Intellectually, morally, and politicallyit epitomized the ethnically diverse Graeco-Roman world, even more than Rome or Constantinople, Antioch or Marseilles. Its famous catechetical school, while sacrificing none of its famous passion for orthodoxy since the days of Pantaenus, Clement of Alexandria, Origen of Alexandria, Dionysius and Theognostus, had begun to take on an almost secular character in the comprehensiveness of its interests, and had counted influential pagans among its serious auditors.

SOLUTION:
What was Rome known for?