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:
Pistillate flowers have a compound ovary with ____ locules topped by three sticky, sessile stigmas.\Question: Choose the right answer from options given a) zero b) three c) six d) seven

Ex Output:
b


Ex Input:
Songbirds have ____ sets of vocal chords.\Question: Choose the right answer from options given a) six b) two c) eight d) ten

Ex Output:
b


Ex Input:
Scriptures speak of at least ____ ages to come.\Question: Choose the right answer from options given a) five b) no c) zero d) two

Ex Output:

d