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]: Nodes are points in space that have ____ probability for locating an electron there.\Question: Choose the right answer from options given a) no b) six c) zero d) three
[A]: c


[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
[A]: a


[Q]: Most queens cope well with ____ to six kittens.\Question: Choose the right answer from options given a) four b) two c) nine d) five
[A]:
a