The set of values of b for which $2\log_{1/36}(bx+28)=-\log_6(12-4x-x^2)$ has exactky one solution is

Question

$\begin{array}{1 1}(A)\;(-\large\frac{14}{9},\normalsize\infty)&(B)\;(-\infty,-14)\cup (\large\frac{14}{3},\normalsize \infty)\\(C)\;(-\infty,-14)\cup \{4\}\cup (\large\frac{14}{3},\normalsize \infty)&(D)\;\{4\}\end{array} $