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: Normal cells have ____ copies of each chromosome.\Question: Choose the right answer from options given a) two b) five c) eight d) no

Output: a


Input: Consider Input: Urea cycle requires the coordination of ____ different tissues.\Question: Choose the right answer from options given a) two b) four c) nine d) zero

Output: a


Input: Consider Input: Elephants replace their teeth ____ to six times in their lifetime.\Question: Choose the right answer from options given a) three b) no c) one d) four


Output: d