Might/may/can have?

Question: What a dangerous thing to do! You______have been killed!
A. may
B. can
C. must
D. might
I chose B, but the correct answer is D. Please explain to me why. If D is correct, why A is wrong?

You cannot say "You can have been killed".

'might' is correct because it refers to past action.

But I learned that may is also used in the past. May and might are interchangeable. Accordingly, if might is correct, may should be correct, too.

tmnt53But I learned that may is also used in the past. May and might are interchangeable. Accordingly, if might is correct, may should be correct, too.

In my variety of English, 'You may have been killed' means 'It is possible that you were killed'. This is clearly not possible when you are speaking to a person who was not killed.

Thank you so much. I got it.