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]: Echinoderms usually have ____ appendages, but there are some exceptions.\Question: Choose the right answer from options given a) ten b) five c) seven d) three
[EX A]: b

[EX Q]: Bees possess ____ eyes.\Question: Choose the right answer from options given a) three b) five c) one d) ten
[EX A]: b

[EX Q]: Cubs stay with their mothers from ____ and a half to three years.\Question: Choose the right answer from options given a) nine b) four c) ten d) one
[EX A]:
d