evidence of sea floor spreading. topographic mapping of mountain ranges. an analysis of soil at the plate boundaries. volcanic activity along coastlines.
I gave my students this multiple choice question: The Theory of Plate Tectonics is based on

Only one answer is correct among these 4 choices:
- evidence of sea floor spreading.
- topographic mapping of mountain ranges.
- an analysis of soil at the plate boundaries.
- volcanic activity along coastlines.

Could you tell me which one is correct?

evidence of sea floor spreading.