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: Blood pressure is measured by ____ numbers.\Question: Choose the right answer from options given a) zero b) eight c) two d) seven
Example Output: c

Example Input: Pups get their sight in about ____ days.\Question: Choose the right answer from options given a) five b) six c) ten d) nine
Example Output: c

Example Input: Pear trees require six to ____ years to produce a commercial crop.\Question: Choose the right answer from options given a) four b) eight c) six d) two
Example Output:
b