Let $\mathbf { F } ( x , y , z ) = - y \mathbf { i } + x \mathbf { j } + z \mathbf { k }$

Multiple Choice

Let $\mathbf { F } ( x , y , z ) = - y \mathbf { i } + x \mathbf { j } + z \mathbf { k }$ and C be the boundary of $x ^ { 2 } + y ^ { 2 } \leq 4$ on the xy-plane. Using Stokes' Theorem, $\int _ { C } ^ { \mathbf { F } } \cdot \mathbf { T } d s$ is

A) 9?
B) 8?
C) 7?
D) 6?
E) 5?