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').

Input: Consider Input: Sexual maturity occurs at three to four years for females and ____ to five years for males.\Question: Choose the right answer from options given a) nine b) seven c) five d) four

Output: d


Input: Consider Input: Songbirds have ____ sets of vocal chords.\Question: Choose the right answer from options given a) six b) two c) eight d) ten

Output: b


Input: Consider Input: Endometriosis is a puzzling disease affecting an estimated ____ million women in the United States.\Question: Choose the right answer from options given a) three b) four c) two d) five


Output: d