Based on the Age of the Light- and Dark-Colored Regions

Multiple Choice

Based on the age of the light- and dark-colored regions of the Moon and the number of craters observed in these regions, we know that impacts in the inner Solar System

A) rapidly decreased approximately 1 billion years ago.
B) rapidly decreased approximately 3 billion years ago.
C) were very rare in the last 4.6 billion years.
D) occurred at approximately a constant rate throughout most of the age of the Solar System.
E) never occur anymore.