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: One way to divide hunter-gatherer groups is by their return systems. James Woodburn uses the categories "immediate return" hunter-gatherers for egalitarian and "delayed return" for nonegalitarian. Immediate return foragers consume their food within a day or two after they procure it. Delayed return foragers store the surplus food (Kelly, 31).
What is the only way to divide hunter-gatherer groups?

Passage: The traditional energy supply of Thuringia is lignite, mined in the bordering Leipzig region. Since 2000, the importance of environmentally unfriendly lignite combustion has declined in favour of renewable energies, which reached an amount of 40% (in 2013), and more clean gas combustion, often carried out as Cogeneration in the municipal power stations. The most important forms of renewable energies are Wind power and Biomass, followed by Solar energy and Hydroelectricity. Furthermore, Thuringia hosts two big pumped storage stations: the Goldisthal Pumped Storage Station and the Hohenwarte Dam.
What is Thuringia's new energy supply?

Passage: People who climb mountains or fly in non-pressurized fixed-wing aircraft sometimes have supplemental O
2 supplies.[h] Passengers traveling in (pressurized) commercial airplanes have an emergency supply of O
2 automatically supplied to them in case of cabin depressurization. Sudden cabin pressure loss activates chemical oxygen generators above each seat, causing oxygen masks to drop. Pulling on the masks "to start the flow of oxygen" as cabin safety instructions dictate, forces iron filings into the sodium chlorate inside the canister. A steady stream of oxygen gas is then produced by the exothermic reaction.
Who sometimes have supplemental O supplies?