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]: Potential energy is divided into ____ different types of energy.\Question: Choose the right answer from options given a) eight b) three c) zero d) two
[EX A]: b

[EX Q]: Metabolism have ____ stages-catabolism and anabolism.\Question: Choose the right answer from options given a) nine b) two c) five d) three
[EX A]: b

[EX Q]: Natural ytterbium is a mixture of ____ stable isotopes.\Question: Choose the right answer from options given a) three b) seven c) ten d) one
[EX A]:
b