Given a sentence with a missing word, pick the answer option that best fills out the missing word in the sentence. Indicate each answer with its index ('a', 'b', 'c', 'd').

Q: Living cells have at least ____ parts.\Question: Choose the right answer from options given a) seven b) three c) zero d) four

A: b
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Q: Casinos have no windows and they have ____ clocks.\Question: Choose the right answer from options given a) six b) four c) eight d) no

A: d
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Q: Today there are ____ non-Euclidean geometries of particular interest to students of mathematics.\Question: Choose the right answer from options given a) one b) three c) two d) no

A:
b
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