Answer:
a. true
Step-by-step explanation:
It is true that the plates of the Earth's crust may also contribute to maintaining upper mantle convection. Mantle convection is the creeping motion of Earth's solid silicate mantle. This movement is caused by the convection currents which carry heat from the interior to the planet's surface. At the surface, the litosphere is divided into plates, and these plates are continuously being created and consumed by this process.