Hiya!
The answer to your question is B.
Physical Properties.
~Hope this helps~
I think the correct answer from the choices listed above is the second option. The <span> idea of plate tectonics was difficult for many scientists to accept for many years after it was first introduced because there </span><span>was no explanation yet for how it was happening. It was only to the recent times that these were proven. </span>
The answer is Tectonic Plates
