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: The Slavic autonym *Slovenin is usually considered (e.g. by Roman Jakobson) a derivation from slovo "word", originally denoting "people who speak (the same language)," i.e. people who understand each other, in contrast to the Slavic word denoting "foreign people" nemci, meaning "mumbling, murmuring people" (from Slavic *nem "mumbling, mute").

SOLUTION: Who came up with the Slavic autonym?

PROBLEM: Passage: In Ancient Greece, green and blue were sometimes considered the same color, and the same word sometimes described the color of the sea and the color of trees. The philosopher Democritus described two different greens; cloron, or pale green, and prasinon, or leek green. Aristotle considered that green was located midway between black, symbolizing the earth, and white, symbolizing water. However, green was not counted among of the four classic colors of Greek painting; red, yellow, black and white, and is rarely found in Greek art.

SOLUTION: How many blues did Democritus describe?

PROBLEM: Passage: Bermuda's pink sand beaches and clear, cerulean blue ocean waters are popular with tourists. Many of Bermuda's hotels are located along the south shore of the island. In addition to its beaches, there are a number of sightseeing attractions. Historic St George's is a designated World Heritage Site. Scuba divers can explore numerous wrecks and coral reefs in relatively shallow water (typically 3040 ft or 912 m in depth), with virtually unlimited visibility. Many nearby reefs are readily accessible from shore by snorkellers, especially at Church Bay.

SOLUTION:
What are located along the shore of the coral reefs?