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:
Fats come in ____ different forms saturated and unsaturated.\Question: Choose the right answer from options given a) no b) two c) six d) seven

Ex Output:
b


Ex Input:
Infants usually die of pneumonia or other infections before reaching ____ years of age.\Question: Choose the right answer from options given a) nine b) four c) zero d) eight

Ex Output:
b


Ex Input:
Thermal equilibrium is when ____ systems reach same temperature.\Question: Choose the right answer from options given a) two b) seven c) five d) three

Ex Output:

a