Why Do Some Elements Generate More Than One Peak in X-Ray

Why do some elements generate more than one peak in X-ray spectroscopy?

A) when an electron is ejected from the atom, one falls in to fill the gap, which generates another gap and and another electron falling
B) electrons can be ejected and rebasorbed many times
C) bonds break and change the electron configurations of some atoms
D) electron bombardment can temporarily change a nucleus to another element
E) none of the above