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:
Poles CAN occur at ____ frequency.\Question: Choose the right answer from options given a) six b) four c) zero d) eight

Ex Output:
c


Ex Input:
Pups get their sight in about ____ days.\Question: Choose the right answer from options given a) five b) six c) ten d) nine

Ex Output:
c


Ex Input:
Dust can reach as high as ____ miles above the surface and settles very slowly.\Question: Choose the right answer from options given a) eight b) six c) two d) zero

Ex Output:

b