Hello
The kinetic energy K of a moving object is:

where m is the mass and v the velocity of the object.
Using this formula, we can calculate v for this problem:
Nitrogen (like70ish % and oxygen like 20%)
-- Radio waves. (To hear the weather while I'm waking up.)
-- Light waves. (To see where the dog is so I don't step on him.)
-- Infrared waves. (To make my toast for breakfast.)
-- Microwaves. (To heat my oatmeal for breakfast. Also when I go in to my job as a microwave communications engineer.)
The Answer is A, the iris dilates the pupil.