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: Classes play ____ distinct roles in object-oriented programming.\Question: Choose the right answer from options given a) eight b) zero c) two d) no

A: c
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Q: Atoms are extremely small, on the order of a few ____ billionths of a meter.\Question: Choose the right answer from options given a) ten b) seven c) nine d) eight

A: a
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Q: Parthenogenesis occurs in ____ fashions.\Question: Choose the right answer from options given a) two b) one c) nine d) six

A:
a
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