Answer:
The moon's surface has been struck with other objects.
Explanation:
Answer 1 - Craters are not a sign of alien life as there is nothing directly showing the crater's are not natural phenomena.
Answer 2 - Craters are (normally) produced by the impact force of a foreign object that is moving quickly and collides with an object of larger size.
Answer 3 - Volcanos form mountains and magma tubes, not craters.
Answer 4 - The formation of mountains does not relate to craters in any meaningful way.
