(1 point) Let F(x, y) = -yi+xj and let C be the circle r (t) = (cost) i + (sin t) j, 0 12. A. Compute Note: Your answer should be an expression of x and y; e.g. "3xy-y" B. Compute Note: Your answer should be an expression of x and y; e.g. "3xy -y" C. Compute F-dr Note: Your answer should be a number the whole xy-plane?