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').

Young emus are very vulnerable to disease until they are about ____ months old.\Question: Choose the right answer from options given a) no b) ten c) six d) three
d

Calves remain hidden for much of the time, and are weaned by ____ months of age.\Question: Choose the right answer from options given a) six b) three c) eight d) one
b

Young worms mature in the large intestine in ____ to four months, then begin the cycle anew.\Question: Choose the right answer from options given a) three b) nine c) zero d) five

a