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 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


[Q]: Natural tellurium consists of ____ isotopes.\Question: Choose the right answer from options given a) six b) seven c) eight d) one
[A]: c


[Q]: All children normally wake up four or ____ times each night after dreams.\Question: Choose the right answer from options given a) five b) six c) nine d) four
[A]:
a