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:
Nodes are points in space that have ____ probability for locating an electron there.\Question: Choose the right answer from options given a) no b) six c) zero d) three

Ex Output:
c


Ex Input:
Popular racism seems most prevalent in Italy which saw ____ deaths at the hands of racists.\Question: Choose the right answer from options given a) five b) two c) one d) four

Ex Output:
d


Ex Input:
Mosses have ____ phases in their life cycle.\Question: Choose the right answer from options given a) eight b) five c) no d) two

Ex Output:

d