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.

Ex Input:
Passage: To be considered 'enriched', the uranium-235 fraction should be between 3% and 5%. This process produces huge quantities of uranium that is depleted of uranium-235 and with a correspondingly increased fraction of uranium-238, called depleted uranium or 'DU'. To be considered 'depleted', the uranium-235 isotope concentration should be no more than 0.3%. The price of uranium has risen since 2001, so enrichment tailings containing more than 0.35% uranium-235 are being considered for re-enrichment, driving the price of depleted uranium hexafluoride above $130 per kilogram in July 2007 from $5 in 2001.

Ex Output:
Between what percent fraction range of uranium-235 is uranium regarded as unenriched?

Ex 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.

Ex Output:
What has not been used for clothing since prehistoric times?

Ex Input:
Passage: In January 2015, a customer named Ricardo Brown received a bill from Comcast with his name changed to "Asshole Brown". Brown's wife, Lisa, believed a Comcast employee changed the name in response to the Browns' request to cancel their cable service, an incident in which she was refused a cancellation unless she paid a $60 fee and instead was routed to a retention specialist. Comcast refused to correct the name on their bill after bringing it to the attention of numerous customer service outlets for the company by explaining that Ricardo is the legal name of the customer, so the Browns turned to consumer advocate Christopher Elliott. Elliott posted the facts of the incident, along with a copy of the bill, on his blog. Shortly thereafter, Elliott contacted Comcast and Comcast offered the Browns an apology, a $60 refund, and a promise to track down and fire the responsible employee. The Browns instead requested a full refund for their negative experience and Comcast agreed to refund the family the last two years of service and provide the next two years of service at no charge. Comcast released a statement explaining: "We have spoken with our customer and apologized for this completely unacceptable and inappropriate name change. We have zero tolerance for this type of disrespectful behavior and are conducting a thorough investigation to determine what happened. We are working with our customer to make this right and will take appropriate steps to prevent this from happening again."

Ex Output:
What was the name of the Comcast employee that changed Ricardo's name?