The Greenhouse Effect, Which Heats a Planet's Surface Above the Predicted

Multiple Choice

The greenhouse effect, which heats a planet's surface above the predicted equilibrium surface temperature for the planet without an atmosphere, is far less effective on Mars than on Earth. Why is this?

A) The Martian surface temperature is very low, and this reduces the effectiveness of the greenhouse effect.
B) There is less energy being conducted upward from the Martian interior to the surface of Mars because of the thickness of its crust compared to that of Earth.
C) The Martian atmosphere contains no gases that can absorb solar radiation.
D) The Martian atmosphere is very thin and traps less infrared radiation from the surface.