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: Downtown San Diego is the central business district of San Diego, though the city is filled with business districts. These include Carmel Valley, Del Mar Heights, Mission Valley, Rancho Bernardo, Sorrento Mesa, and University City. Most of these districts are located in Northern San Diego and some within North County regions.

SOLUTION: What is the central business district of downtown San Diego?

PROBLEM: Passage: On 7 February 2007, the French Parliament passed a bill granting COM status to both St. Barthélemy and (separately) to the neighbouring Saint Martin. The new status took effect on 15 July 2007, when the first territorial council was elected, according to the law. The island has a president (elected every five years), a unicameral Territorial Council of nineteen members who are elected by popular vote and serve for five-year terms, and an executive council of seven members. Elections to these councils were first held on 1 July 2007 with the last election in March 2012.

SOLUTION: What is COM short for?

PROBLEM: Passage: Drinking chilled beer began with the development of artificial refrigeration and by the 1870s, was spread in those countries that concentrated on brewing pale lager. Chilling beer makes it more refreshing, though below 15.5 °C the chilling starts to reduce taste awareness and reduces it significantly below 10 °C (50 °F). Beer served unchilled—either cool or at room temperature, reveal more of their flavours. Cask Marque, a non-profit UK beer organisation, has set a temperature standard range of 12°–14 °C (53°–57 °F) for cask ales to be served.

SOLUTION:
What began in the 1780s?