Assertion (A) : If $\mathrm{A}>0. \mathrm{B}>0$ and $\mathrm{A}+\mathrm{B}=\frac{\mathrm{\pi }}{3}$then the maximum value of $\mathrm{TanA} \mathrm{TanB}$ is $\frac{1}{3}$

Reason (R) : If ${\mathrm{a}}_1+{\mathrm{a}}_2+{\mathrm{a}}_3+\dots +{\mathrm{a}}_{\mathrm{n}}=\mathrm{k}$ (constant) then value of ${\mathrm{a}}_1{\mathrm{a}}_{2 }\dots {\mathrm{a}}_{\mathrm{n}}$ is greatest when ${\mathrm{a}}_1={\mathrm{a}}_{2 }\dots \dots {\mathrm{a}}_{\mathrm{n}}.$