Convective flow in the Earth's mantle involves some materials rising while others are sinking based on the relative materials OA. hardnesses OB. textures Oc. densities OD. lusters of the

C.

Convection occurs due to the different relative densities of materials.

Explanation:

Heating within the Earth lowers the density of parts of the Earth's mantle. In areas where these lower-density materials lie beneath cooler, higher-density materials, an unstable condition develops. To stabilize this condition, the cooler, higher-density materials flow downward while the hotter, lower-density materials flow upward. This vertical flow of material is called convection.

I did this on Study Island.