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').

Ex Input:
Female elephants have babies about ____ years apart, and they have only one each time.\Question: Choose the right answer from options given a) eight b) one c) zero d) three

Ex Output:
d


Ex Input:
Black women die from cervical cancer at ____ times the rate of white women.\Question: Choose the right answer from options given a) five b) one c) two d) three

Ex Output:
d


Ex Input:
Buttercups can grow up to ____ to three feet tall and can be about an inch across.\Question: Choose the right answer from options given a) nine b) one c) zero d) eight

Ex Output:

b