The rate of plate movement is only a few per year so climate changes triggered by shifting plates happen on a scale of millions of years.

centimeters

Explanation:

The lithospheric plates move relative to the others at a very slow but continuous speed that is, on average, about five centimeters per year. This movement is ultimately driven by the unequal distribution of heat inside the Earth. The hot material found in the depths of the mantle moves slowly upwards and serves as a part of our planet's internal convection system. Simultaneously, colder and denser sheets of the oceanic lithosphere descend to the mantle, moving the rigid outer layer of the Earth into motion. Finally, the titanic friction between Earth's lithospheric plates generates earthquakes, creates volcanoes and deforms large masses of rock in the mountains.  But it causes climate changes to be experienced every million years.

the answer would be b).