The figure below shows a sodium current (bottom trace) elicited by stepping the membrane potential from-70 mV to 0 mV (top trace). The dashed line is O nA. Upon depolarizing the membrane, there is an inward current. This whole-cell current is a reflection of the cumulative activity of many individual ion channels. What is the probable state of an individual sodium channel at each point (A, B, and C)? 0 mV -70 mV 0 2 time (ms) 4