I would say that plate tectonics shows what the origin of volcanic activity, earthquakes and mountains comes from their collision or subduction. Where two plates collide mountains can be formed (uplift), where subduction occurs then volcanic activity like in the circum-pacific belt occurs and where stresses build up in subduction or transform fault (like the San Andreas Fault) and are suddenly released, earthquakes are the result. Subduction is where the oceanic plate gets pushed under the continental plate.
B. Conspicuously in this context means attracting attention.
