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:
Gases are perhaps the best understood of the ____ states of matter.\Question: Choose the right answer from options given a) three b) five c) nine d) zero

Ex Output:
a


Ex Input:
Microwave ovens emit ____ kinds of radiation.\Question: Choose the right answer from options given a) six b) two c) four d) eight

Ex Output:
b


Ex Input:
Most amphibians also have ____ limbs.\Question: Choose the right answer from options given a) one b) six c) four d) five

Ex Output:

c


