Answer:
The correct option is A: "However much United States voters may agree that"
Explanation:
Option B is wrong because there is nothing parallel to the option “that the government as a whole spends beyond its means.”
Option C is also wrong because it has similar parallelism error as it is in option C
Option D looks great but we are looking for certainty and not uncertainty. "May" makes it sound uncertain.
Option E seems correct because parallelism is ok here but the sentence in the option followed by a comma makes it wrong.
Option A is the correct option because parallelism is ok there and the "much" in the sentence modifys the verb phrase "voters may agree".