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: Many people have ____ symptoms until they suffer chest pains or a heart attack.\Question: Choose the right answer from options given a) three b) one c) no d) seven

Output: c


Input: Consider Input: Mammals have only ____ sets of teeth.\Question: Choose the right answer from options given a) six b) five c) seven d) two

Output: d


Input: Consider Input: Acupuncture works to relieve ____ types of lower back pain.\Question: Choose the right answer from options given a) nine b) two c) six d) five


Output: b