Final answer:
The best example of parallelism in the passage is "The controversy surrounding" and "The controversy will rage," as it uses repetition of a phrase with different verbs and conclusions.
Step-by-step explanation:
The best example of parallelism found within the given passage is "The controversy surrounding" and "The controversy will rage". This choice demonstrates parallel structure by repeating the phrase 'The controversy' at the start of consecutive sentences, but each time the phrase leads to a different verb and conclusion. This technique emphasizes the persistence and intensity of the debate over flag burning as a form of protest. Both freedom of conscience and powerful forms of communication are crucial to the underlying issue, but for parallelism in linguistic terms, repeating grammatical structures creates the strongest effect.