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]: Females can only have four babies at ____ time.\Question: Choose the right answer from options given a) no b) one c) nine d) three
[A]: b


[Q]: Motor neurons are divided into ____ groups.\Question: Choose the right answer from options given a) two b) six c) seven d) eight
[A]: a


[Q]: Women are ____ times as likely as men to get osteoporosis.\Question: Choose the right answer from options given a) four b) no c) zero d) two
[A]:
a