What is the rock that has no exposure to chemical or mechanical weathering known as? subsoil topsoil regolith bedrock

Subsoil: layer of soil under topsoil on the surface of the ground
Topsoil: fertile, upper part of soil
Regolith: unconsolidated residual or transported material that overlies the solid rock on the earth
Bedrock: lies under regolith, can be 100 meters undersurface.
Order of surface: Topsoil --> Subsoil --> Regolith --> Bedrock

Your answer is bedrock

The answer is bedrock