Radiation is energy that is

A. not transferred at all

B, transferred by direct contact of two objects

C. transferred by moving air currents

D. transferred by electomagnetic waves

It is d. It is a form of energy that can travel through space. For example, we receive the heat from the sun, which is located very far from the earth via radiation. The sun's heat is not transmitted through any solid medium, but through a vacuum. This is possible by electromagnetic waves.