The area of the shaded portion is:

$\left(\pi-\frac{8}{3}\right)$ sq. units $\left(\frac{8}{3}+\pi\right)$ sq. units $\left(\frac{\pi}{2}-\frac{4}{3}\right)$ sq. units $\left(\frac{\pi}{2}+\frac{4}{3}\right)$ sq. units

$\left(\pi-\frac{8}{3}\right)$ sq. units

The correct answer is Option (1) - $\left(\pi-\frac{8}{3}\right)$ sq. units