I believe that's is answer C because your ask about and increasment on the velocity in this observation
Thermal, electrical, chemical, nuclear, and electromagnetic energy. (just gave you more than two just incase)
When a system experiences a disturbance ( such as concentration, temperature, or pressure changes), it will respond to restore a new equilibrium state.
RADIATION. Radio waves, microwaves, IR, light, UV, x-rays, GAMMA waves etc are ALL Electromagnetic radiation. The difference between ALL the above is the frequency, I.E. The number of waves per second. The higher the frequency the more energy.
Ion, any atom or group of atoms that bears one or more positive or negative electrical charges. Positively charged ions are called cations; negatively charged ions, anions.