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:
Cows breed at ____ years, bulls at four.\Question: Choose the right answer from options given a) two b) three c) seven d) one

Ex Output:
b


Ex Input:
Quarks also come in ____ 'colours', terms for a property a little like electrical charge.\Question: Choose the right answer from options given a) three b) nine c) six d) no

Ex Output:
a


Ex Input:
Glands have lobules - but liver lobules defined in ____ different ways.\Question: Choose the right answer from options given a) three b) one c) two d) zero

Ex Output:

a