Which statement best describes initial vs secondary radiation?

• A. Primary radiation consists of Bremmstrahlung; Secondary consists of Characteristic
• B. Primary radiation consists of Bremmstrahlung or Characteristic; Secondary consists of Photoelectric, Compton, and Coherent
• C. Primary radiation consists of Photoelectric; Secondary consists of Bremmstrahlung
• D. Primary radiation consists of Bremsstrahlung only; Secondary radiation none

Answer: (B)