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: Chemical interactions are essentially electron interactions of ____ atoms.\Question: Choose the right answer from options given a) six b) no c) ten d) two
Example Output: d

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: Beer is always safe to drink, as ____ pathogens can grow in it.\Question: Choose the right answer from options given a) one b) no c) ten d) six
Example Output:
b