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]: Perennial grass takes ____ to five years before it is mature enough to produce adequate seed.\Question: Choose the right answer from options given a) six b) zero c) three d) no
[EX A]: c

[EX Q]: Elephants give birth to ____ calf every four to nine years on average.\Question: Choose the right answer from options given a) ten b) one c) eight d) six
[EX A]: b

[EX Q]: Females only reproduce every second year and give birth to an average of ____ live young.\Question: Choose the right answer from options given a) no b) five c) one d) six
[EX A]:
d