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').

[EX Q]: Elk retain their antlers for more than ____ months of the year.\Question: Choose the right answer from options given a) nine b) ten c) six d) seven
[EX A]: c

[EX Q]: Hamsters can live to be three to ____ years old.\Question: Choose the right answer from options given a) four b) two c) three d) nine
[EX A]: a

[EX Q]: Puppies can start vaccinations at ____ weeks.\Question: Choose the right answer from options given a) ten b) eight c) six d) two
[EX A]:
c