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: Brain death occurs in just four to ____ minutes unless the heart rhythm is restored.\Question: Choose the right answer from options given a) ten b) three c) six d) nine

A: c
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Q: Sound waves travel through the air in a similar manner, but in all ____ dimensions.\Question: Choose the right answer from options given a) three b) five c) nine d) one

A: a
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Q: Arachnids are terrestrial arthropods, which have simple eyes and ____ pairs of legs.\Question: Choose the right answer from options given a) three b) no c) five d) four

A:
d
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