$\text { Find } \frac { d y } { d x } \text { by implicit differentiation given that } 2 x y = 9 \text {. }$

Multiple Choice

$\text { Find } \frac { d y } { d x } \text { by implicit differentiation given that } 2 x y = 9 \text {. }$

A) $\frac { d y } { d x } = - \frac { 9 y } { x }$
B) $\frac { d y } { d x } = - 9 x y$
C) $\frac { d y } { d x } = - x y$
D) $\frac { d y } { d x } = 9 x y$
E) $\frac { d y } { d x } = - \frac { y } { x }$