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: Trains kill ____ people every year.\Question: Choose the right answer from options given a) zero b) three c) no d) four

A: d
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Q: Some olive trees live to be ____ thousand years old.\Question: Choose the right answer from options given a) ten b) zero c) two d) seven

A: c
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Q: Chimpanzees reach puberty between the age of eight and ____ years.\Question: Choose the right answer from options given a) no b) ten c) six d) nine

A:
b
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