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: Compression is useful because it helps reduce resource usage, such as data storage space or transmission capacity. Because compressed data must be decompressed to use, this extra processing imposes computational or other costs through decompression; this situation is far from being a free lunch. Data compression is subject to a space–time complexity trade-off. For instance, a compression scheme for video may require expensive hardware for the video to be decompressed fast enough to be viewed as it is being decompressed, and the option to decompress the video in full before watching it may be inconvenient or require additional storage. The design of data compression schemes involves trade-offs among various factors, including the degree of compression, the amount of distortion introduced (when using lossy data compression), and the computational resources required to compress and decompress the data.

SOLUTION: What helps reduce trade-offs?

PROBLEM: Passage: Heresy is any provocative belief or theory that is strongly at variance with established beliefs or customs. A heretic is a proponent of such claims or beliefs. Heresy is distinct from both apostasy, which is the explicit renunciation of one's religion, principles or cause, and blasphemy, which is an impious utterance or action concerning God or sacred things.

SOLUTION: What is belief in a strongly held custom?

PROBLEM: Passage: During the Middle Ages, Thuringia was situated at the border between Germanic and Slavic territories, marked by the Saale river. The Ostsiedlung movement led to the assimilation of Slavic people between the 11th and the 13th century under German rule. The population growth increased during the 18th century and stayed high until World War I, before it slowed within the 20th century and changed to a decline since 1990. Since the beginning of Urbanisation around 1840, the Thuringian cities have higher growth rates resp. smaller rates of decline than rural areas (many villages lost half of their population since 1950, whereas the biggest cities (Erfurt and Jena) keep growing).

SOLUTION:
Where was Thuringia attacking in the Middle Ages?