Can someone please help me on these two please Which of the following geologic processes is the BEST evidence that continents change position over time?

A. formation of deltas
B. volcanic eruption
C. erosion by glaciers
D. sea floor spreading

Scientists have observed that when oceanic plates and cotinental plates collide, the oceanic plate is driven under the continental plate. The MOST LIKELY reason for this phenomenon is -

A. the convection currents in the mantle.
B. water applies a downward force on the oceanic plate.
C. the oceanic plate is more dense than the continental plate.
D. the continental plate is wider than the oceanic plate.