Why is the youngest rock found near mid-ocean ridges?

Answer Below, Put it in your own words if this is a typing/writing question

Explanation:

The youngest crust of the ocean floor can be found near the seafloor spreading centers or mid-ocean ridges. As the plates split apart, magma rises from below the Earth's surface to fill in the empty void. ... Like any rock, the plates of basaltic composition become less thick and denser as they cool.

b. lithosphere, asthenosphere, mesosphere   is the answer most likely