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: National immunization vaccinates all children under ____ against polio.\Question: Choose the right answer from options given a) zero b) four c) ten d) five

Answer: b


Question: Songbirds have ____ sets of vocal chords.\Question: Choose the right answer from options given a) six b) two c) eight d) ten

Answer: b


Question: Every insect has six legs, has ____ legs, has six legs.\Question: Choose the right answer from options given a) seven b) one c) zero d) six

Answer:
d