Radiation requires a heated liquid to transfer energy.
a. true
b. false

So we want to know does radiation require a heated liquid to transfer energy. So radiation is and emission of energy trough electro-magnetic waves, more precisely trough the infra-red part of the electromagnetic spectrum. And electromagnetic waves are a transfer of energy that is radiated trough space without any medium required. So the answer to the question is FALSE.

C. the electric current passes from the slip rings, through the brushes, and to the collection device.