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]: Earthworms have ____ pairs of hearts.\Question: Choose the right answer from options given a) seven b) five c) one d) no
[A]: b


[Q]: Mothers usually give birth to one, two, or ____ babies at a time.\Question: Choose the right answer from options given a) three b) zero c) five d) ten
[A]: a


[Q]: Japanese archaeologists recognize, in general terms, ____ prehistoric and four historic periods.\Question: Choose the right answer from options given a) nine b) seven c) one d) four
[A]:
d