Which phrase gives two forces scientists believe are responsible for tectonic plate motion? Question 5 options:

1. friction between the plate and the asthenosphere and pressure of magma on the edge of the plate

2. convection in the mantle and pressure of magma on the edge of the plate

3. gravity acting on the edges of plates and convection in the mantle

4. gravity acting on the edges of plates and friction between the plate and the asthenosphere