How Do the Atmospheres of the Moon and Mercury Compare

Multiple Choice

How do the atmospheres of the Moon and Mercury compare?

A) Mercury's is much denser, like Venus, with much carbon dioxide.
B) They are about equal, each only 1% as dense as ours.
C) The cooler Moon retains a thicker nitrogen atmosphere.
D) As no spacecraft has yet landed there, no information exists about Mercury's atmosphere.
E) Neither body has a permanent true atmosphere.