If $\rho ( x , y , z ) = x$

Multiple Choice

If $\rho ( x , y , z ) = x$ is the volume density function of a solid enclosed by $100 x + 25 y + 16 z = 400$ and all the coordinate planes, its total mass is

A) $\frac { 800 } { 3 }$
B) $\frac { 800 } { 7 }$
C) $\frac { 800 } { 9 }$
D) $\frac { 800 } { 11 }$
E) $\frac { 800 } { 13 }$