Although the Constitution was written to provide states with ample aut

I believe this is a redundancy issue. If I mandate you do something it means you are required to do it. If you must do something it also means you are required to do it.

Thus, if I mandate you that must do something, it is similar to saying, you are required to do that thing you are required to do.

That's how I looked at it...

Can someone please explain why A is right and D is wrong?

Going by the last split - do we require only "have" or "should/must/will have". Since, "mandate" require subjunctive, we require only "have" - this eliminates B, D and E. Between A and C - There is no special significance of perfect tense here, so select A.



Not an expert here, but here's my opinion on your analysis. Except C, there are no verb tense errors here. "mandates" in D is fine.. [ I won't use the word "error" for the usage of perfect tense in C, just that its not required ]
B - "Should" do not imply possibility. The problem is with using "should" with "mandate" ["mandate that" is the key here..], and the same reasoning can be applied to the usage of "must" in E.

Cheers !!

Why not B is the answer!
Same tense!

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Tense is actually not the issue here. We can say "did," but "does" works fine, since the Constitution has not changed in this regard. (It still mandates this.)

The problem with B is "should." We can mandate that something happen (this form is the command subjunctive), or we can say/indicate that something should happen, but we can't mandate that something should happen. It's one or the other.

Could you please explain in detail why is C incorrect?

neelugarg33 Okay, so verb tense *is* an issue for C. The present tense ("has mandated") sounds like this is a recent or current decision, rather than something that was set down once long ago. We can use past or present tense, just as we can say that one of Shakespeare's plays "told a story" (because he made it long ago) or "tells a story" (because you can still read or see it now). We wouldn't say that the play "has told a story." It sounds like something that occurred once, probably recently. It also sounds like the play (or in our original q, the Constitution) actually took this action itself--the Constitution has spoken! If this all sounds very strange for a simple shift in tense, the short answer is that present perfect simply doesn't work this way. It describes either ongoing actions ("I have been working from home since March") or achievements ("I have been to Japan"; "That story has already been told"). Unless used to describe achievements, it doesn't describe things that occurred or were written down once in the past and still apply. We don't say "I have been born in California" or "The Bible has forbidden this."