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: Black bears stand ____ to six feet long and almost three feet at the shoulders when on all fours.\Question: Choose the right answer from options given a) three b) five c) four d) one
Example Output: b

Example Input: Minks travel more than most furbearers, covering up to ____ miles a night.\Question: Choose the right answer from options given a) four b) five c) zero d) ten
Example Output: d

Example Input: Amino acids can exist as ____ enantiomorphs.\Question: Choose the right answer from options given a) no b) three c) two d) ten
Example Output:
c