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:
Copper is ____ times higher in dog liver than in human liver.\Question: Choose the right answer from options given a) three b) ten c) six d) one

Ex Output:
b


Ex Input:
China is reportedly in the top ____ nations in industrial output.\Question: Choose the right answer from options given a) seven b) ten c) three d) five

Ex Output:
b


Ex Input:
Poisonous mushrooms outnumber edible mushrooms more than ____ to one.\Question: Choose the right answer from options given a) eight b) seven c) zero d) ten

Ex Output:

d