Assertion (A) : The range of the function $f(x) = 2 \sin^{-1} x + \frac{3\pi}{2}$, where $x \in [-1, 1]$, is $[\frac{\pi}{2}, \frac{5\pi}{2}]$. Reason (R) : The range of the principal value branch of $\sin^{-1} (x)$ is $[0, \pi]$.