$\"\"$

The parameters $\"\"$ and $\"\"$ describe a sector of a circle with radius $\"\"$ from $\"\"$ to $\"\"$ .

The area of a sector of a circle with radius $\"\"$ and central angle $\"\"$ is $\"\"$ , where $\"\"$ measured in radians.

The angle of the sector is $\"\"$ .

Convert the angle into radian measure.

$\"\"$ .

Substitute the values $\"\"$ and $\"\"$ in $\"\"$ .

$\"\"$

Option B is the correct choice.