Observations of Tectonic Activity Differ on Venus and on Earth

Observations of tectonic activity differ on Venus and on Earth. A reasonable explanation is that on Venus

A) the crust appears to be thicker and is therefore too rigid to break up into moving plates.
B) the surface is broken into only two plates, divided by a line at an angle to the equator.
C) the crust appears to be thinner and weaker and cannot support the creation and motion of solid plates.
D) mantle convection appears to be more vigorous and has broken the lithosphere into a multitude of small plates instead of a few large ones.