Suppose the Utility Function $U = f ( x , y ) \text { is a measure of the utility (or satisfaction) }$

Multiple Choice

Suppose the utility function $U = f ( x , y ) \text { is a measure of the utility (or satisfaction) }$ derived by a person from the consumption of two products x and y. Determine the marginal utility of product if the utility function is $U = - 3 x ^ { 2 } + x y - 8 y ^ { 2 }$

A) $U _ { y } = x - 8 y$
B) $U _ { y } = x - 32 y$
C) $U _ { y } = x - 16 y$
D) $U _ { y } = x + 8 y$
E) $U _ { y } = x + 16 y$