I think that The Continental Drift Theory is true. Because of how the continents did look like they fit together and because the evidence that they found after Wegener's death. Such as the same fresh water animal fossils found on different continents, and the same rock layers found on different continents.
I think that Seafloor Spreading is also a valid theory. Because of all of their evidence, otherwise how would new rock be getting created all of the time other then that. Also it clearly shows how the new rock is being created and how the magma is coming up out of the mid-ocean ridges.
However I do not think the theory of Plate Tectonics is true. And that all this heat can cause the plates to move? I think that heat is not capable of moving something so big. Although convection currents may be true I do not think that plate tectonics is. Because the convection currents heat up, rise, cool down & sink.