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: Brachiopods are superficially similar to bivalves, both having ____ shells.\Question: Choose the right answer from options given a) two b) eight c) seven d) one

Output: a


Input: Consider Input: Shamrocks can be ____ of four leafs.\Question: Choose the right answer from options given a) six b) seven c) zero d) three

Output: d


Input: Consider Input: Female elands reach sexual maturity at ____ years of age.\Question: Choose the right answer from options given a) two b) three c) zero d) six


Output: b