Question

which of the following best explains why mars and venus surface temperatures vary, despite both planets having atmospheres that contain mostly carbon dioxide? (1 point)
mars has a surface of red rocks and sand which reflect heat.
mars has a thin atmosphere that cannot hold much heat.
venus has a thick atmosphere which blocks heat from the surface.
venus has a surface of high mountains which absorb heat.

Explanation:

Mars has a thin atmosphere, so it can't retain heat well compared to Venus. Venus has a thick atmosphere with a strong greenhouse - effect, causing high surface temperatures. Mars' thin atmosphere is the main factor in the temperature difference despite similar atmospheric composition in terms of carbon - dioxide content.

Answer:

Mars has a thin atmosphere that cannot hold much heat.