I think I highlighted all of the correct answers? But there can't be more than one answer, so I'm pretty sure I'm missing something, but I can't think of what...

I think D is the correct answer; wait, why did you choose A and e?

Which one violates Aufbau Principle ? means not following it. Electrons in higher energy levels before filling lower energy shells.
A is the answer .
Rest all EC are correct according to Aufbau principle.

ohh wait yes I read the question wrong, the answer is A

oh, ok thank you!