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: In 1906, the tungsten filament was introduced. Tungsten metal was initially not available in a form that allowed it to be drawn into fine wires. Filaments made from sintered tungsten powder were quite fragile. By 1910, a process was developed by William D. Coolidge at General Electric for production of a ductile form of tungsten. The process required pressing tungsten powder into bars, then several steps of sintering, swaging, and then wire drawing. It was found that very pure tungsten formed filaments that sagged in use, and that a very small "doping" treatment with potassium, silicon, and aluminium oxides at the level of a few hundred parts per million greatly improved the life and durability of the tungsten filaments.
What was introduced in 1900?

Passage: After just 100 hours of ground combat, and with all of Kuwait and much of southern Iraq under coalition control, US President George H. W. Bush ordered a cease-fire and negotiations began resulting in an agreement for cessation of hostilities. Some US politicians were disappointed by this move, believing Bush should have pressed on to Baghdad and removed Hussein from power; there is little doubt that coalition forces could have accomplished this if they had desired. Still, the political ramifications of removing Hussein would have broadened the scope of the conflict greatly, and many coalition nations refused to participate in such an action, believing it would create a power vacuum and destabilize the region.
How long did ground combat operations last in the Kuwait Gulf War?

Passage: The time and space hierarchy theorems form the basis for most separation results of complexity classes. For instance, the time hierarchy theorem tells us that P is strictly contained in EXPTIME, and the space hierarchy theorem tells us that L is strictly contained in PSPACE.
What does not form the basis for most separation results of complexity classes?