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]: Nymphs feed and mature through ____ instars in about six to eight weeks.\Question: Choose the right answer from options given a) four b) eight c) five d) no
[A]: c


[Q]: Fever usually lasts for an average of ____ days in adults.\Question: Choose the right answer from options given a) zero b) three c) nine d) two
[A]: b


[Q]: Choirs usually sing in several parts, most often in ____ parts.\Question: Choose the right answer from options given a) four b) two c) one d) zero
[A]:
a