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: Many tractors have ____ wheel drive to get extra grip on the hills and in wet conditions.\Question: Choose the right answer from options given a) four b) seven c) five d) two

A: a
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Q: Electrolytic capacitors have a finite lifetime, usually about ____ years.\Question: Choose the right answer from options given a) zero b) ten c) four d) eight

A: b
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Q: Women devote their lives to raising families of six, seven and ____ children.\Question: Choose the right answer from options given a) one b) zero c) two d) eight

A:
d
****