If $\;A=\small\frac{1}{\pi}$$\begin{bmatrix}sin^{-1}(\pi x) &tan^{-1}\big(\frac{\pi}{x}\big)\\ sin^{-1}\big(\frac{\pi}{x} \big)&cot^{-1}(\pi x)\end{bmatrix}\;$ and $\;B=\small\frac{1}{\pi}$$\begin{bmatrix}-cos^{-1}(\pi x) &tan^{-1}\big(\frac{x}{\pi}\big)\\ sin^{-1}\big(\frac{x}{\pi} \big)&-tan^{-1}(\pi x)\end{bmatrix}$ then $A-B$ is equal to

Question

$(A)\;I \quad(B)\;0\quad(C)\;2I\quad(D)\;\frac{1}{2} I$