Answer:
Due to absence of erosive agents.
Step-by-step explanation:
The Maria have few craters compared to the surrounding areas because of no erosive agents such as winds and rain. The erosive agents only formed when there is atmosphere in the region. The atmosphere is responsible for the presence of winds and rainfall. If these erosive agents are present, there will be more craters as compared to the region where no erosive agents are present so that's why Maria have few craters in the region. as compared to the surrounding region.