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: Wind is renewable, and produces ____ emissions or by-products.\Question: Choose the right answer from options given a) five b) nine c) zero d) no
Example Output: d

Example Input: Statistics show that within ____ years of divorce, many people marry a second time.\Question: Choose the right answer from options given a) four b) nine c) six d) three
Example Output: d

Example Input: Porcupines grow for ____ or four years before they reach adult body size.\Question: Choose the right answer from options given a) three b) nine c) eight d) six
Example Output:
a