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]: Parliamentary democracy is less than ____ years old in Nigeria.\Question: Choose the right answer from options given a) eight b) two c) nine d) three
[A]: b


[Q]: All spider mites have ____ legs and a lack of a separate head.\Question: Choose the right answer from options given a) eight b) four c) ten d) one
[A]: a


[Q]: Retraction requires the contraction of ____ internal muscles.\Question: Choose the right answer from options given a) two b) nine c) ten d) six
[A]:
a