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: Babies show an interest in solid foods when they are approximately four to ____ weeks old.\Question: Choose the right answer from options given a) nine b) eight c) five d) six

A: c
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Q: Babies are breast-fed until about ____ years of age.\Question: Choose the right answer from options given a) four b) nine c) eight d) two

A: d
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Q: Flu strikes within ____ to three days after exposure to the virus.\Question: Choose the right answer from options given a) six b) one c) seven d) zero

A:
b
****