There is no atmosphere on the moon, because ___________
(a) It is closer to the earth and also it has inactive inter gases in it
(b) It is too far from the sun and also it has very low pressure on its outer surface
(c) Escape velocity of gas molecules is greater than their root mean square velocity
(d) Escape velocity of gas molecules is less than their root mean square velocity
I have been asked this question in semester exam.
This intriguing question comes from Intensity of Gravitational Field in section Mechanical Properties of Solids of Engineering Physics I