The resting memebrane potential of smooth muscle is:

(70 - 80 mV): Ref: 55, 68, 78-G, 154 - 803-SL (84- Ganong 23rd)* The resting membrane potential of skeletal muscle cardiac muscle, NMJ is about - 90 mV* The resting membrane potential in neurons a bout - 70 mV* The resting membrane potential in other sensory receptor cells is usually 70-90 mV however in the visual receptor the RMP is about - 40 mVThe RMP in visceral smooth muscle ranges - 50 and 75 mV, sometimes it reaches the low level of - 25. The pecularity of the RMP is that very much unstable (154-SL)* The option 'A' is probably correct regarding range (- 50 - 75 mV)