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: Female bilbies have a backward-opening pouch with ____ nipples.\Question: Choose the right answer from options given a) no b) two c) five d) eight

Output: d


Input: Consider Input: Vampires generally are male, and rabies is ____ times more frequent in men than in women.\Question: Choose the right answer from options given a) no b) two c) zero d) seven

Output: d


Input: Consider Input: Pyrimidines have ____ rings and purines have one.\Question: Choose the right answer from options given a) two b) five c) nine d) ten


Output: a