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: 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

Answer: a

Question: Water softeners add sodium to drinking water in ____ ways.\Question: Choose the right answer from options given a) zero b) six c) two d) nine

Answer: c

Question: Children get frequent viral infections during the first five or ____ years of life.\Question: Choose the right answer from options given a) ten b) six c) five d) one

Answer:
b