Final answer:
The correct answer to the question is A) Parallel structures, as the sentence illustrates the use of similar grammatical patterns to equate the importance of two ideas, 'high unemployment' and 'large deficits.' It is also a compound sentence.
Step-by-step explanation:
The given sentence, "According to some economists, neither high unemployment nor large deficits will keep the economy from rebounding," demonstrates the use of a parallel structure. This grammatical construction uses similar patterns of words to show that two or more ideas have the same level of importance. The sentence aligns the concepts of 'high unemployment' and 'large deficits' to suggest that neither of these factors is potent enough to prevent an economic rebound. It is also an example of a compound sentence, as it connects two independent clauses through a coordinating conjunction without any dependent clause present, indicating two separate but related ideas.