Although there are other ways energy can be transferred from one place to another, radiation is the only way energy can get from the sun to the Earth. Why is this? A. Only radiation can cover such large distances as those between the Earth and the sun.

B. Only radiation does not require matter and there are no particles in open space.

C. The sun only emits energy in the form of radiation.

D. Radiation is not the only way energy moves from the sun to the Earth.

I believe it's C, but I'm not sure.