Final Answer:
The best explanation for the movement of lithospheric plates is d. convection cells generated by gravity and heat flow in the mantle. Thus the correct option is d.
Step-by-step explanation:
The movement of lithospheric plates is primarily driven by convection currents in the mantle, a process linked to gravity and heat flow. As the Earth's interior heats up due to the decay of radioactive isotopes and the residual heat from its formation, warmer, less dense material rises towards the surface, while cooler, denser material descends. This process generates convection cells in the mantle, and the dragging force of these cells propels the lithospheric plates above them, causing their horizontal movement.
Convection cells driven by gravity and heat flow provide a comprehensive explanation for plate tectonics, encompassing the complex dynamics of Earth's interior. These movements influence various geological phenomena such as seafloor spreading, subduction, and the formation of mountain ranges. Understanding the connection between mantle convection and plate motion is crucial in earth sciences, helping scientists and geologists predict and comprehend geological events like earthquakes and volcanic activity. The interplay of gravity and heat flow in the mantle creates a dynamic system that shapes the Earth's surface over geological time scales, and this explanation remains a fundamental concept in the field of plate tectonics.