Answer:
D). I want to go on vacation, my mom and dad, traveling overseas.
Step-by-step explanation:
Parallelism employs repetition of elements in a sentence that are of identical or similar grammatical form in a sentence that aids to propose a parallel structure to the sentence. It serves to enhance the readability of the sentence and assists to offer an organized form to the ideas so that it becomes easy for the readers to understand.
As per the question, the sentence that does not follow parallelism is displayed through option D as it fails to employ a similar grammatical form of the verb('go' is not parallel to 'traveling') which diminishes the meaning and affects the readability of the sentence. The other options are reflecting a parallel construction. Thus, option D is the correct answer.