Use Stokes' Theorem to Calculate the Circulation of the Field $\mathbf { F } = x ^ { 2 } \mathbf { i } + x y \mathbf { j } + y \mathbf { k } ; \mathrm { C }$

Use Stokes' Theorem to calculate the circulation of the field F around the curve C in the indicated direction.
- $\mathbf { F } = x ^ { 2 } \mathbf { i } + x y \mathbf { j } + y \mathbf { k } ; \mathrm { C }$ : the counterclockwise path around the perimeter of the rectangle in the $x - y$ plane formed from the $x$ -axis, $y$ -axis, $x = 2$ and $y = 3$

A) 18
B) 9
C) -18
D) - 9