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').

Example 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
Example Output: c

Example Input: Smallmouth bass grow to ____ inches in their first growing season.\Question: Choose the right answer from options given a) five b) four c) seven d) ten
Example Output: a

Example Input: Tumor viruses are of ____ distinct types.\Question: Choose the right answer from options given a) nine b) ten c) two d) zero
Example Output:
c