Which region of the moon is probably older one covered by a thick layer of regolith or one covered by a thin layer of regolith?

The region of the Moon covered by a thin layer of regolith is likely the older one. This is because a thick layer of regolith typically indicates more recent impacts and volcanic activity, which continuously disrupts and re-covers the surface. In contrast, areas with thin regolith have experienced less geological activity and are often more ancient, preserving older features. Thus, the thickness of regolith can serve as an indicator of the relative age of lunar surfaces.