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 Q]: Birds have ____ eyes.\Question: Choose the right answer from options given a) eight b) five c) nine d) two
[EX A]: d

[EX Q]: Poles CAN occur at ____ frequency.\Question: Choose the right answer from options given a) six b) four c) zero d) eight
[EX A]: c

[EX Q]: Caterpillars have two pairs of ____ ocelli on their head.\Question: Choose the right answer from options given a) zero b) eight c) nine d) six
[EX A]:
d