Consider the vector field F= (y-x.x) and curve C: r(t) = (7 cos t,7 sin t) for Osts 2x. K a. Based on the picture, make a conjecture about whether the circulation of F on C is positive, negative, or zero. b. Compute the circulation. a. Choose the best answer below. OA. The circulation is probably close to zero because the vector field is nearly symmetric across a line that passes through the center of the circle. OB. The circulation is probably positive because the vector field resembles a counterclockwise rotation field. OC. The circulation is probably positive because the vector field resembles a clockwise rotation field. b. The circulation is (Type an exact answer, using a as needed.)