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: Potassium helps maintain fluid regulation and normal pH. All ____ help normalize.\Question: Choose the right answer from options given a) three b) six c) two d) one

A: a
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Q: Fluorescent lamps are roughly ____ times more intense than ordinary lightbulbs.\Question: Choose the right answer from options given a) six b) one c) three d) eight

A: c
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Q: Most birds of prey have three toes in front on their feet , and ____ toe in the back.\Question: Choose the right answer from options given a) one b) no c) zero d) six

A:
a
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