43. From the electric field vector at a point, one can determine which of the following?
I. The direction of the electrostatic force on a test charge of known sign at that point
II. The magnitude of the electrostatic force exerted per unit charge on a test charge at that point
III. The electrostatic charge at that point
(A) I only
(B) III only
(C) I and II only
(D) II and III only
(A) I only
(B) III only
(C) I and II only
(D) II and III only