The Relatively Few Craters That We See Within the Lunar

The relatively few craters that we see within the lunar maria

A) were formed by impacts that occurred before those that formed most of the craters in the lunar highlands.
B) were formed by impacts that occurred after those that formed most of the craters in the lunar highlands.
C) were created by the same large impactor that led to the formation of the maria.
D) are volcanic in origin,rather than from impacts.
E) are sinkholes that formed when sections of the maria collapsed.