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:
Potential energy is divided into ____ different types of energy.\Question: Choose the right answer from options given a) eight b) three c) zero d) two

Ex Output:
b


Ex Input:
Most endocrinologists see patients every ____ months throughout the pregnancy.\Question: Choose the right answer from options given a) six b) two c) zero d) three

Ex Output:
b


Ex Input:
Elves typically have ____ children or fewer.\Question: Choose the right answer from options given a) four b) one c) no d) five

Ex Output:

a