Infrared radiations are produced when a changing electric field creates a

a.) longitudinal wave perpendicular to it
b.) changing magnetic field parallel to it
c.) changing magnetic field perpendicular to it
d.) longitudinal wave parallel to it

Option (C)

Explanation:

The electromagnetic waves are produced by accelerating charge or the oscillating charge particles.

When electric field vector and magnetic field vector are at right angles to each other interacts, then electromagnetic waves are produced. They propagate in the perpendicular direction of both electric field vector and magnetic field vector.

The examples of electromagnetic waves are gamma rays, X rays, visible rays, infrared rays, micro waves, etc.

i think the answer is a, hope this : )

there are no contact forces mentioned on the list of choices that you've provided.