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: Female cats have ____ X's in each cell.\Question: Choose the right answer from options given a) five b) two c) one d) ten
Example Output: b

Example Input: Most internal parasites are specific to one or ____ species.\Question: Choose the right answer from options given a) seven b) three c) two d) five
Example Output: c

Example Input: Uncontrolled diabetes can increase risk by up to ____ times.\Question: Choose the right answer from options given a) five b) four c) seven d) eight
Example Output:
b