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:
Onion thrips experience ____ instars.\Question: Choose the right answer from options given a) three b) six c) eight d) four

Ex Output:
d


Ex Input:
Mosquitoes have ____ distinctive life stages, with the first three stages being spent in the water.\Question: Choose the right answer from options given a) four b) zero c) nine d) five

Ex Output:
a


Ex Input:
Nipple clamps increase sensation in ____ main ways.\Question: Choose the right answer from options given a) no b) zero c) eight d) two

Ex Output:

d