heat from the sun moves through space by the process of\na circulation.\nb conduction.\nc convection.\nd…

Answer:

D. radiation

Explanation:

Step1: Understand heat - transfer processes

Circulation is not a fundamental heat - transfer process in this context. Conduction requires a material medium for heat transfer (atoms or molecules to vibrate and transfer energy). Convection also requires a fluid medium (liquid or gas) for heat transfer through the movement of the fluid itself. Radiation is the transfer of heat energy in the form of electromagnetic waves and can occur through a vacuum.

Step2: Analyze heat transfer from the sun

The sun's heat moves through the vacuum of space to reach the Earth. Since there is no material medium (solid, liquid, or gas) in space for conduction or convection to occur, the heat transfer from the sun to the Earth is by radiation.