In the production of X-rays, the term "bremsstrahlung" refers to which of the following? A. The cut-off wavelength, Amin, of the X-ray tube B. The discrete X-ray lines emitted when an electron in an outer orbit fills a vacancy in an inner orbit of the atoms in the target metal of the X-ray tube C. The discrete X-ray lines absorbed when an electron in an inner the X- ray tube D. The smooth, continuous X-ray spectra produced by high-energy blackbody radiation from the X-ray tube E. The smooth, continuous X-ray spectra produced by rapidly decelerating electron in the target metal of the X-ray tube