Solve the Problem $\mathrm { D } = [ 0,96 ] \times [ 0,132 ]$

Solve the problem.
-The northern third of Indiana is a rectangle measuring 96 miles by 132 miles. Thus, let $\mathrm { D } = [ 0,96 ] \times [ 0,132 ]$ . Assuming that the total annual snowfall (in inches) , $\mathrm { S } ( \mathrm { x } , \mathrm { y } )$ , at $( \mathrm { x } , \mathrm { y } ) \in \mathrm { D }$ is given by the function $\mathrm { S } ( \mathrm { x } , \mathrm { y } ) = 60$ $\mathrm { e } ^ { - 0.001 ( 2 \mathrm { x } + \mathrm { y } ) }$ with $( \mathrm { x } , \mathrm { y } ) \in \mathrm { D }$ , find the average snowfall on $D$ .

A) 52.44 inches
B) 52.06 inches
C) 51.14 inches
D) 51.78 inches