Find the Mass of the Solid in the First Octant $x + y + z = 1$

Multiple Choice

Find the mass of the solid in the first octant bounded by the coordinate planes and the plane $x + y + z = 1$ , where the density is $\rho ( x , y , z ) = 12 x y$

A) $\frac { 1 } { 8 }$
B) $\frac { 1 } { 10 }$
C) $\frac { 1 } { 12 }$
D) $\frac { 1 } { 14 }$