The Voltage-gated sodium channel

What is the value of the membrane potential when the inactivation gate of the voltage-gated sodium channel closes the channel (preventing further entry of$$\mathrm{Na}+$$)? (A)$$+70\mathrm{mV}$$(B)$$-91\mathrm{mV}$$(C)$$-55\mathrm{mV}$$(D)$$+35\mathrm{mV}$$