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').
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Question: Elephants give birth to one calf every ____ to nine years on average.\Question: Choose the right answer from options given a) no b) four c) three d) seven

Answer: b


Question: Dogs are pack animals, and ____ dogs is the minimum number for proper socialization.\Question: Choose the right answer from options given a) four b) five c) no d) zero

Answer: b


Question: Fireflies have ____ main body parts.\Question: Choose the right answer from options given a) zero b) two c) nine d) three

Answer:
d