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.

Example Input: Passage: The use of animal fur in clothing dates to prehistoric times. It is currently associated in developed countries with expensive, designer clothing, although fur is still used by indigenous people in arctic zones and higher elevations for its warmth and protection. Once uncontroversial, it has recently been the focus of campaigns on the grounds that campaigners consider it cruel and unnecessary. PETA, along with other animal rights and animal liberation groups have called attention to fur farming and other practices they consider cruel.
Example Output: What has not been used for clothing since prehistoric times?

Example Input: Passage: The National Incident Based Reporting System (NIBRS) crime statistics system aims to address limitations inherent in UCR data. The system is used by law enforcement agencies in the United States for collecting and reporting data on crimes. Local, state, and federal agencies generate NIBRS data from their records management systems. Data is collected on every incident and arrest in the Group A offense category. The Group A offenses are 46 specific crimes grouped in 22 offense categories. Specific facts about these offenses are gathered and reported in the NIBRS system. In addition to the Group A offenses, eleven Group B offenses are reported with only the arrest information. The NIBRS system is in greater detail than the summary-based UCR system. As of 2004, 5,271 law enforcement agencies submitted NIBRS data. That amount represents 20% of the United States population and 16% of the crime statistics data collected by the FBI.
Example Output: What system do Canadian law enforcement agencies use?

Example Input: Passage: The Archaic period in the Americas saw a changing environment featuring a warmer more arid climate and the disappearance of the last megafauna. The majority of population groups at this time were still highly mobile hunter-gatherers; but now individual groups started to focus on resources available to them locally, thus with the passage of time there is a pattern of increasing regional generalization like, the Southwest, Arctic, Poverty, Dalton and Plano traditions. This regional adaptations would become the norm, with reliance less on hunting and gathering, with a more mixed economy of small game, fish, seasonally wild vegetables and harvested plant foods.
Example Output:
Which period in the Americas saw an unchanging environment?