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: Women account for more than ____ out of five deaths from stroke.\Question: Choose the right answer from options given a) three b) six c) eight d) nine
Example Output: a

Example Input: Many tractors have ____ wheel drive to get extra grip on the hills and in wet conditions.\Question: Choose the right answer from options given a) four b) seven c) five d) two
Example Output: a

Example Input: Nymphs pass through ____ nymphal instars before molting into the adult stage.\Question: Choose the right answer from options given a) eight b) ten c) nine d) five
Example Output:
d