Question

The Sun transfers energy to the atmosphere primarily by _____.

conduction
convection
radiation
all of the above

Answer 1

It would have to be radiation. (C)

Step-by-step explanation:

For one, the question says "primarily", meaning most likely it only wants a single answer, excluding D. Second, we know that the sun admits radiation through simple science, excluding A and B, leaving C as the final answer!

Answer 2

The answer is radiation.

Between earth's atmosphere and the sun there is vacuum in which heat cannot be transferred by conduction or convection for which you need solid material or fluid. That means that sun is radiating energy which travels in vacuum and reaches earth.