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

Ex Output:
d


Ex Input:
All butterflies go through ____ life stages .\Question: Choose the right answer from options given a) one b) four c) zero d) five

Ex Output:
b


Ex Input:
Acoustic guitars come in ____ types.\Question: Choose the right answer from options given a) two b) ten c) one d) four

Ex Output:

a