Answer:
A. 1613 °C
Explanation:
The asthenosphere is located just below the Earth’s crust.
It must be molten or semi-molten, so that convection currents can move the tectonic plates above it.
Rocks start to melt at about 1300 °C, so a temperature of 1613 °C sounds about right.
Searching "electron configuration of chromium on google images will easily provide you with the answer.
It's a chemical change because it's changing the object's property.

As depth increases, the density of the layers decreases.