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:
Centrifugal pumps can usually handle up to about ____ percent by volume of air.\Question: Choose the right answer from options given a) one b) five c) eight d) seven

Ex Output:
b


Ex Input:
Nymphs feed and mature through five instars in about ____ to eight weeks.\Question: Choose the right answer from options given a) six b) five c) seven d) zero

Ex Output:
a


Ex Input:
Some care providers begin contraceptives as early as ____ days postpartum, or as late as four weeks.\Question: Choose the right answer from options given a) six b) two c) five d) zero

Ex Output:

c