Choose the correct version of the sentence.
a. top athletes train long hours, eating healthy diets and dedicate themselves to their sports.
b. top athletes train long hours, eat healthy diets, and dedicate themselves to their sports.
c. top athletes train long hours, eat healthy diets, and dedicating themselves to their sports.
d. top athletes training long hours, eating healthy diets and dedicate themselves to their sports.

The correct answer is option B because of PARALLELISM as regards structure.

In "Top athletes train long hours, eat healthy diets, and dedicate themselves to their sports" we have three verbs conjugated in Simple Present Tense (train, eat, and dedicate).

Another important detail is the use of comma before the conjunction "and" which is correct when enumerating.

The rest of the options break the parallelism for what they are incorrect.

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