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.

[Q]: 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.
[A]: What does not form the basis for most separation results of complexity classes?


[Q]: Passage: Hirsch held the opinion that Judaism demands an application of Torah thought to the entire realm of human experience, including the secular disciplines. His approach was termed the Torah im Derech Eretz approach, or "neo-Orthodoxy". While insisting on strict adherence to Jewish beliefs and practices, he held that Jews should attempt to engage and influence the modern world, and encouraged those secular studies compatible with Torah thought. This pattern of religious and secular involvement has been evident at many times in Jewish history. Scholars[who?] believe it was characteristic of the Jews in Babylon during the Amoraic and Geonic periods, and likewise in early medieval Spain, shown by their engagement with both Muslim and Christian society. It appeared as the traditional response to cultural and scientific innovation.
[A]: Who held that Judaism demands an application of the bible through human experience?


[Q]: Passage: The efficiency of a Rankine cycle is usually limited by the working fluid. Without the pressure reaching supercritical levels for the working fluid, the temperature range the cycle can operate over is quite small; in steam turbines, turbine entry temperatures are typically 565 °C (the creep limit of stainless steel) and condenser temperatures are around 30 °C. This gives a theoretical Carnot efficiency of about 63% compared with an actual efficiency of 42% for a modern coal-fired power station. This low turbine entry temperature (compared with a gas turbine) is why the Rankine cycle is often used as a bottoming cycle in combined-cycle gas turbine power stations.[citation needed]
[A]:
What limits the Rankine cycle's temperatures?