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: 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: Vision disorders affect ____ in every four school-age children.\Question: Choose the right answer from options given a) nine b) one c) five d) six

Output: b


Input: Consider Input: Humans are bipeds who stand between five to ____ feet in height when fully grown.\Question: Choose the right answer from options given a) ten b) six c) four d) one


Output: b