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:
Potassium helps maintain fluid regulation and normal pH. All ____ help normalize.\Question: Choose the right answer from options given a) three b) six c) two d) one

Ex Output:
a


Ex Input:
Japan is a highly urbanised country, with approximately three in every ____ people living in cities.\Question: Choose the right answer from options given a) seven b) two c) four d) eight

Ex Output:
c


Ex Input:
Roots grow mostly sideways and can extend up to ____ times the height of the tree.\Question: Choose the right answer from options given a) five b) ten c) three d) no

Ex Output:

c