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: Most aphthous ulcers heal in one to ____ weeks.\Question: Choose the right answer from options given a) two b) eight c) one d) seven
Example Output: a

Example Input: Most toddlers find it hard to sit still for more than a few seconds, let alone ____ minutes.\Question: Choose the right answer from options given a) no b) three c) four d) zero
Example Output: b

Example Input: Maxillary molars have ____ buccal cusps and two lingual cusps.\Question: Choose the right answer from options given a) nine b) six c) two d) four
Example Output:
c