X-ray graph (characteristic X-rays)

[Matejxx1]

Homework Statement

4. On which graph are the characteristic X-rays being portrayed correctly.

Homework Equations

The Attempt at a Solution

ok I know that characteristic X-rays happen because the electrons in outer shells move to the lowest possible energy shell and that the change in energy equals the energy of the emited X-rays
My question now looking at the picture I don't quite know why the graphs D and B are incorrect , I know that A can't be true and that C is the correct answer, but can someone explain to me why D and B are wrong ?
Thanks

 

[mfb]

B has a line where it should not have one.
D: The energy levels are at high energies and close together which looks suspicious, but I don't think you can clearly rule it out without numbers.

 

[Matejxx1]

thanks for the answer
Yeah that is what I was thinking
D: is it completely impossible for an atom to emit x rays which are at high energie levels? and does an atom always emit X-rays only at the end part of the graph

 

[Matejxx1]

Update : I asked the professor why B could not be the right. his reply was :" B is not the wrong answer C is just more right." and he also said if I had choosen B he would not have marked it as a wrong answer

 

[mfb]

Oh, well... fine.