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: In 1797, Patrick Colquhoun was able to persuade the West Indies merchants who operated at the Pool of London on the River Thames, to establish a police force at the docks to prevent rampant theft that was causing annual estimated losses of £500,000 worth of cargo. The idea of a police, as it then existed in France, was considered as a potentially undesirable foreign import. In building the case for the police in the face of England's firm anti-police sentiment, Colquhoun framed the political rationale on economic indicators to show that a police dedicated to crime prevention was "perfectly congenial to the principle of the British constitution." Moreover, he went so far as to praise the French system, which had reached "the greatest degree of perfection" in his estimation.

SOLUTION: Who convinced the East Indies merchants in London to establish police?

PROBLEM: Passage: Machine vision systems often require bright and homogeneous illumination, so features of interest are easier to process. LEDs are often used for this purpose, and this is likely to remain one of their major uses until the price drops low enough to make signaling and illumination uses more widespread. Barcode scanners are the most common example of machine vision, and many low cost products use red LEDs instead of lasers. Optical computer mice are an example of LEDs in machine vision, as it is used to provide an even light source on the surface for the miniature camera within the mouse. LEDs constitute a nearly ideal light source for machine vision systems for several reasons:

SOLUTION:  non-LEDs are often used for what type of systems?

PROBLEM: Passage: The FBI's chief tool against organized crime is the Racketeer Influenced and Corrupt Organizations (RICO) Act. The FBI is also charged with the responsibility of enforcing compliance of the United States Civil Rights Act of 1964 and investigating violations of the act in addition to prosecuting such violations with the United States Department of Justice (DOJ). The FBI also shares concurrent jurisdiction with the Drug Enforcement Administration (DEA) in the enforcement of the Controlled Substances Act of 1970.

SOLUTION:
What is the FBI's least used tool against organized crime?