$\"\"$

Observe the diagram :

The length of the rectangle is $\"\"$ .

Breadth of the rectangle is $\"\"$ .

Area of the square with side of $\"\"$ is $\"\"$ .

The area of the shaded region: $\"\"$ .

$\"\"$

Therefore the area of the shaded region is $\"\"$ .

The correct choice is $\"\"$ .

$\"\"$

The correct choice is $\"\"$ .