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: Turkey also has ____ inland drainage basins.\Question: Choose the right answer from options given a) zero b) two c) eight d) nine
Example Output: b

Example Input: Trains kill ____ people every year.\Question: Choose the right answer from options given a) zero b) three c) no d) four
Example Output: d

Example Input: Tribal peoples teach that there are ____ parts to any ceremony, each equally important.\Question: Choose the right answer from options given a) four b) nine c) ten d) seven
Example Output:
a