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.

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.
What has not been used for clothing since prehistoric times?

Passage: In 1872, Russian Alexander Lodygin invented an incandescent light bulb and obtained a Russian patent in 1874. He used as a burner two carbon rods of diminished section in a glass receiver, hermetically sealed, and filled with nitrogen, electrically arranged so that the current could be passed to the second carbon when the first had been consumed. Later he lived in the USA, changed his name to Alexander de Lodyguine and applied and obtained patents for incandescent lamps having chromium, iridium, rhodium, ruthenium, osmium, molybdenum and tungsten filaments, and a bulb using a molybdenum filament was demonstrated at the world fair of 1900 in Paris.
Who did not patent an incandescent light bulb in 1872?

Passage: Following the 11 September 2001 attacks, former President of Pakistan Pervez Musharraf sided with the U.S. against the Taliban government in Afghanistan after an ultimatum by then U.S. President George W. Bush. Musharraf agreed to give the U.S. the use of three airbases for Operation Enduring Freedom. United States Secretary of State Colin Powell and other U.S. administration officials met with Musharraf. On 19 September 2001, Musharraf addressed the people of Pakistan and stated that, while he opposed military tactics against the Taliban, Pakistan risked being endangered by an alliance of India and the U.S. if it did not cooperate. In 2006, Musharraf testified that this stance was pressured by threats from the U.S., and revealed in his memoirs that he had "war-gamed" the United States as an adversary and decided that it would end in a loss for Pakistan.
Which former president sided with the Taliban?