It $\mathrm{y}=\mathrm{g}(\mathrm{x})$ is a curve which is obtained by the reflecton of $y=f(x)=\frac{e^{x}-e^{-x}}{2}$ by the line $y=x$ then
(A) $\mathrm{y}=\mathrm{g}(\mathrm{x})$ has exactly one tangent parallel to $\mathrm{x}$-axis
(B) $\mathrm{y}=\mathrm{g}(\mathrm{x})$ has no tangent parallel to $\mathrm{y}$-axis
(C) The tangent to $y=g(x)$ at $(0,0)$ is $y=x$
(D) $g(x)$ has no extremum