Sentence Correction (SC) | Re: Although the Constitution was written to provide states with ample aut

Hi Verbal Expert,

Could you help clarify why A is right? I arrived at the right answer, but I want to ensure via the right reasoning.

b -> implies possibility when the meaning of the sentence dictates necessary
c -> verb tense
d -> verb tense
e -> this was the other option I was contemplating; must implies mandatory meaning which would be appropriate given the sentence meaning (allow freedom, but mandate republican form of government)

Thank you for helping me along my GMAT journey