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:
Alleles segregate independently yielding ____ possible allelic combinations in gametes.\Question: Choose the right answer from options given a) ten b) one c) four d) nine

Ex Output:
c


Ex Input:
Butterflies have ____ stages in their life cycle.\Question: Choose the right answer from options given a) two b) four c) no d) eight

Ex Output:
b


Ex Input:
Infertility affects about one in ____ couples of child-bearing age.\Question: Choose the right answer from options given a) one b) six c) three d) seven

Ex Output:

b