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:
Carbon forms ____ bonds.\Question: Choose the right answer from options given a) five b) four c) two d) three

Ex Output:
b


Ex Input:
Poisons come in ____ different forms .\Question: Choose the right answer from options given a) four b) no c) five d) ten

Ex Output:
a


Ex Input:
Love is the physical and mental compatibility of ____ people.\Question: Choose the right answer from options given a) three b) four c) two d) ten

Ex Output:

c