Answer: Correct option is Option D.
Explanation:
Processed foods are bad for you, are high in fat, and are the cause of serious health issues.
Parallel structures are those structures where words are used in same pattern in a sentence to show that two given ideas/phrases are of similar significance.
This sentence uses parallel structure correctly.
Parallel structure in the sentence are -
are bad for you
are high in fat
are the cause of serious health issues
