Question

How is radiation different from convection and conduction?

Answer 1

Difference Between Conduction, Convection and Radiation:
While conduction is the transfer of heat energy by direct contact, convection is the movement of heat by actual motion of matter; radiation is the transfer of energy with the help of electromagnetic waves.

So I would agree with C. Radiation can move through empty space, whereas conduction and convection require matter to transfer heat (by movement or direct contact).