The equilibrium constant for the reaction

$(()-)-$

is $3\mathrm{.}6$ at $25C.$ If $K_a$ for $C{H}_3\frac{C}{O}OH$ is $1\mathrm{.}8{10}^{-5},$ what is the acid dissociation constant for $C_6{H}_5\frac{C}{O}OH?$

A$.5\mathrm{.}0{10}^{-6}$

B$.6\mathrm{.}5{10}^{-5}$

C$.2\mathrm{.}3{10}^{-4}$

D$.8\mathrm{.}3{10}^{-5}$

E$.5\mathrm{.}6{10}^{-6}$