Mark (√) against the correct answer in the following: Let $f: R-\left\{\frac{-4}{3}\right\} \rightarrow-\left\{\frac{4}{3}\right\}: f(x)=\frac{4 x}{(3 x+4)}$. Then $f^{-1}(y)=?$ A. $\frac{4 y}{(4-3 y)}$ B. $\frac{4 y}{(4 y+3)}$ C. $\frac{4 y}{(3 y-4)}$ D. None of these