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').

[Q]: Pupae usually transform into adults ____ to three days later.\Question: Choose the right answer from options given a) one b) two c) no d) eight
[A]: b


[Q]: Some male fish return after just ____ years.\Question: Choose the right answer from options given a) no b) two c) one d) six
[A]: b


[Q]: Rice hulls are quite stable, lasting up to ____ years in the soil.\Question: Choose the right answer from options given a) seven b) ten c) four d) five
[A]:
b