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: In early 12th-century al-Andalus, the Arabian philosopher, Ibn Tufail (Abubacer), wrote discussions on materialism in his philosophical novel, Hayy ibn Yaqdhan (Philosophus Autodidactus), while vaguely foreshadowing the idea of a historical materialism.

SOLUTION: When was Ibn Tufail born?

PROBLEM: Passage: The noise-based speed is defined as the exposure that will lead to a given signal-to-noise ratio on individual pixels. Two ratios are used, the 40:1 ("excellent image quality") and the 10:1 ("acceptable image quality") ratio. These ratios have been subjectively determined based on a resolution of 70 pixels per cm (178 DPI) when viewed at 25 cm (9.8 inch) distance. The signal-to-noise ratio is defined as the standard deviation of a weighted average of the luminance and color of individual pixels. The noise-based speed is mostly determined by the properties of the sensor and somewhat affected by the noise in the electronic gain and AD converter.

SOLUTION: Which ratio was subjectively determined?

PROBLEM: Passage: The dominant land plant species of the time were gymnosperms, which are vascular, cone-bearing, non-flowering plants such as conifers that produce seeds without a coating. This is opposed to the earth's current flora, in which the dominant land plants in terms of number of species are angiosperms. One particular plant genus, Ginkgo, is thought to have evolved at this time and is represented today by a single species, Ginkgo biloba. As well, the extant genus Sequoia is believed to have evolved in the Mesozoic.

SOLUTION:
What plant species died out in the Mesozoic?