The correct option is D strikes the metal target
X-rays are produced when a stream of electrons in an X-ray tube strikes the metal target. X-rays are high energy electromagnetic radiations. X-rays have a wavelength ranging from 0.01 to 10 nanometers, and frequencies in the range 3×1016 Hz to 3×1019 Hz) and energies in the range 100 eV to 100 keV.