The correct answer is (d). The escape velocity of gas molecules on the moon is less than the root mean square velocity. This means that gas molecules on the moon have enough energy to escape the moon’s gravity and fly off into space. As a result, there is no atmosphere on the moon.
Option (a) is incorrect because the moon’s proximity to the earth does not affect its atmosphere. The earth’s atmosphere is held in place by the earth’s gravity, and the moon’s gravity is too weak to hold onto an atmosphere.
Option (b) is incorrect because the moon receives light from the sun, but this does not affect its atmosphere. The sun’s light does not provide enough energy to keep gas molecules from escaping the moon’s gravity.
Option (c) is incorrect because the moon’s revolution around the earth does not affect its atmosphere. The moon’s gravity is too weak to hold onto an atmosphere, regardless of whether it is revolving around the earth or not.