Answer:
B. Convection current
Explanation:
When denser materials replace lighter materials, it is called convection current.
This is one of the driving mechanism of the plate motion between the crust and the mantle.
- During convection, hot mantle molten rocks rises to the surface as they become lighter.
- Denser crustal rocks are colder and more solid packed, they sink further into the earth.
- This forms a series of convection cells driven by the high temperature of the mantle.
- The cyclic transition between these two plates corresponds to the convection current which carries heat way.
Therefore, the solution is convection current.
