The surface of Mercury has many more craters than the surface of Earth has. Which of the following statements best explains why Mercury has many more craters than Earth has?

Lacking the actual choices I assume mass, magnetic field, Atmosphere, or the Moon.

Explanation:

Mercury is 4,879 km, which is approximately 38% the diameter of Earth. ie barely larger than the moon. answer was also supposed to include the presence of the moon, a magnetic field only 1.1 % the strength of Earth, and lacks a protective atmosphere to burn up / reduce the size of meteors.