Find the Mass of the Lamina Described by the Inequalities $0 \leq x \leq 4 \text { and } 0 \leq y \leq 8 \text {, }$

Multiple Choice

Find the mass of the lamina described by the inequalities $0 \leq x \leq 4 \text { and } 0 \leq y \leq 8 \text {, }$ given that its density is $\rho ( x , y ) = 2 x y$ . (Hint: Some of the integrals are simpler in polar coordinates.)

A) 768
B) 128
C) 512
D) 256
E) 392