Use the gradient vector to find the tangent line to the level curve f(x, y) = 12 at the point (4, 3).
A. y - 3 = 4(x - 4)
B. y - 3 = -4(x - 4)
C. y - 4 = 3(x - 3)
D. y - 4 = -3(x - 3)