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 cattle have a ____ chambered stomach, consisting of a rumen, reticulum, omasum and abomasum.\Question: Choose the right answer from options given a) ten b) four c) six d) two
[A]: b


[Q]: Some homeopathic remedies are so dilute, ____ molecules of the healing substance remain.\Question: Choose the right answer from options given a) ten b) three c) one d) no
[A]: d


[Q]: Postzygotic isolation exists between the ____ frog species.\Question: Choose the right answer from options given a) nine b) two c) eight d) five
[A]:
b