Meteors were only named once as a possible cause for craters. The size of the moon was not told in the story. The story said that areas of the moon are covered with powdery dust, but craters were not formed from it. The story did not say anything about rockets. The story said areas covered by powdery dust reflect a lot of light.
Rough surfaces reflect less light.
Therefore the dust has nothing to do with rough surfaces. The story did not say anything about walls of ice. The story says that the moon's large craters can only be seen with a telescope. A is correct. Choose the letter that marks the answer that most closely matches the numbered word or meaning.