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: 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: Stroke is the number ____ cause of death in the United States.\Question: Choose the right answer from options given a) ten b) nine c) one d) three
Example Output: d

Example Input: Some women have ____ or more children by different men.\Question: Choose the right answer from options given a) nine b) five c) two d) eight
Example Output:
b