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').

Input: Consider Input: Females reach sexual maturity around ____ to five year-olds.\Question: Choose the right answer from options given a) four b) five c) one d) ten

Output: a


Input: Consider Input: 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

Output: b


Input: Consider Input: Gobies are relatively small fish, usually reaching ____ inches in captivity.\Question: Choose the right answer from options given a) eight b) two c) ten d) three


Output: d