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: Smoking is responsible for one out of ____ American deaths.\Question: Choose the right answer from options given a) five b) six c) nine d) seven
Example Output: a

Example Input: Healthcare providers diagnose ____ general types of insomnia.\Question: Choose the right answer from options given a) two b) eight c) one d) three
Example Output: a

Example Input: Interval logic translates a ____ bit value to a note number.\Question: Choose the right answer from options given a) ten b) four c) seven d) six
Example Output:
b