If $\large\frac{5+2\sqrt 3}{7+4\sqrt 3}$$=a+b\sqrt 3$ then the value of $a$ and $b$ is

Question

$\begin{array}{1 1}(A) \; a=11,b=6\\(B)\;a=-11,b=-6 \\(C)\;a=11,b=-6 \\(D)\;a=-11,b=6 \end{array}$