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: Children are more likely than adults to show ____ symptoms even if they are infected.\Question: Choose the right answer from options given a) eight b) two c) no d) six
Example Output: c

Example Input: All spider mites have ____ legs and a lack of a separate head.\Question: Choose the right answer from options given a) eight b) four c) ten d) one
Example Output: a

Example Input: Mice have four leg-foot assemblies and ____ tail assembly per body.\Question: Choose the right answer from options given a) five b) ten c) one d) zero
Example Output:
c