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: Many scientists believe the neutrino has ____ mass at all.\Question: Choose the right answer from options given a) eight b) zero c) two d) no

A: d
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Q: Collars come in ____ shapes.\Question: Choose the right answer from options given a) six b) two c) four d) zero

A: b
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Q: Mosquitoes live four to ____ weeks.\Question: Choose the right answer from options given a) eight b) ten c) seven d) nine

A:
a
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