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: Calves can swim ____ days after they are born.\Question: Choose the right answer from options given a) ten b) two c) zero d) one

A: b
****
Q: Mammals have only ____ sets of teeth.\Question: Choose the right answer from options given a) six b) five c) seven d) two

A: d
****
Q: Domestic violence affects at least one out of ____ American families.\Question: Choose the right answer from options given a) two b) five c) no d) four

A:
d
****