When We Consider a Thin Horizontal Layer of the Atmosphere

Multiple Choice

When we consider a thin horizontal layer of the atmosphere, of thickness dy, of area A, with pressure P on the bottom, with an average mass m per molecule, and nV molecules per unit volume, the magnitude of the difference of the pressure at the top and bottom of the layer is given by dP =

A) mgdy.
B) mgnVdy.
C) mgAdy.
D) mgnVAdy.
E) mgnVAPdy.