Answer:A. Energy: Energy can be quantized. For example, in quantum mechanics, the energy levels of electrons in an atom are quantized.
B. Radiation: Radiation can be quantized. Electromagnetic radiation is quantized in the form of photons, each with a specific energy.
C. Number of people in a room: The number of people in a room is inherently quantized because you can only have whole numbers of people (1, 2, 3, etc.), not fractions.
D. Electric charge: Electric charge is quantized. For example, the charge of an electron is a fundamental unit of charge.
Since all the options listed (Energy, Radiation, Number of people in a room, Electric charge) can be quantized, the correct answer is:
E. All can be quantized.
Explanation: