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]: All baleen whales have ____ blow holes.\Question: Choose the right answer from options given a) zero b) four c) seven d) two
[A]: d


[Q]: Motor neurons are divided into ____ groups.\Question: Choose the right answer from options given a) two b) six c) seven d) eight
[A]: a


[Q]: Ringed seals are the main prey of polar bears that catch about ____ seal every six and a half days.\Question: Choose the right answer from options given a) two b) zero c) no d) one
[A]:
d