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]: Young squirrels remain in the nest for about ____ weeks.\Question: Choose the right answer from options given a) seven b) six c) two d) eight
[EX A]: b

[EX Q]: Brachiopods are superficially similar to bivalves, both having ____ shells.\Question: Choose the right answer from options given a) two b) eight c) seven d) one
[EX A]: a

[EX Q]: Gas occupies some volume in ____ dimensional space.\Question: Choose the right answer from options given a) eight b) no c) four d) three
[EX A]:
d