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

A: b
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Q: Most marine sediments are of ____ basic types.\Question: Choose the right answer from options given a) three b) ten c) two d) nine

A: c
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Q: Every cell has ____ long flagella.\Question: Choose the right answer from options given a) two b) eight c) five d) nine

A:
a
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