The albedo of earth's surface is only about 4%, yet the combined albedo of earth and its atmosphere is about 30%. which set of conditions below best explains why this is so?

For the answer to the question above, I believe the answer to these is high albedo of clouds, low albedo of water

Clouds have higher albedo because of its color which is white, White clouds deflect more sunlight and UV back to the outer space than the ocean which absorbs the heat of the sunlight