scientists can test differences of the area with pigmentation by observing which is lighter and which is darker however they use microscope to look the difference of the pigmentation over the cells.
Over population if i recall correctly
The answer is; D
The plasticity of rock in the mantle and the convection currents in the region are responsible for tectonic plate movements. The hot molten rock from deep in the mantle rise and is replaced by the cooler rock at the upper mantle. These convections are similar to those of water in a boiling pot. As the tectonic plates move (as they are dragged by these convections) and collide, earthquakes are caused. In addition, at subductions zones (where two plates collide) there occurs high volcanic activity.
It can become a sedimentary rock over time because of weathering. sedimentary rocks are rocks that have been broken down over time by water and erosion. hope this helps.
