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:
Reservoirs cover an area of the planet ____ times the size of Britain.\Question: Choose the right answer from options given a) two b) eight c) three d) six

Ex Output:
d


Ex Input:
Polyester has ____ favorable properties.\Question: Choose the right answer from options given a) four b) two c) seven d) six

Ex Output:
b


Ex Input:
Elephants have ____ toes on the fore feet and four on the hind feet.\Question: Choose the right answer from options given a) two b) no c) three d) five

Ex Output:

d