Parallel structure does all of the following but

A. create choppy, uneven sentences
B. create emphasis on important ideas
C. create patterns of clauses or phrases
D. create rhythm and balance of ideas

A. create choppy, uneven sentences

The correct answer is A. create choppy, uneven sentences.

To determine the correct answer, we need to understand what parallel structure is and its purpose.

Parallel structure, also known as parallelism, is the use of grammatical structures that are grammatically similar in form, sound, or meaning. It involves constructing sentences or phrases in the same pattern to create balance, rhythm, and clarity in writing.

Option A states that parallel structure creates choppy, uneven sentences. This is not correct because parallel structure actually improves the flow and coherence of sentences by maintaining a consistent structure.

Option B states that parallel structure creates emphasis on important ideas. This is a correct statement. By using parallelism, writers can highlight crucial information and make it more memorable for readers.

Option C states that parallel structure creates patterns of clauses or phrases. This is another correct statement. Parallelism helps in creating patterns, making texts more organized and easier to understand.

Option D states that parallel structure creates rhythm and balance of ideas. This is also correct. By using parallel structure, writers can achieve a pleasingly rhythmic and balanced flow of ideas in their writing.

Based on the explanations above, it can be concluded that the correct answer is: A. create choppy, uneven sentences.