In Cells Where the Equilibrium Potential for Cl^- Equals the Resting

In cells where the equilibrium potential for Cl^- equals the resting potential, opening Cl^- channels in the subsynaptic membrane

A) has no effect on the probability of the postsynaptic cell reaching threshold since there's no movement of Cl^-.
B) increases the probability of the postsynaptic cell reaching threshold since the entry of Na⁺ into the cell (through another route) will make the cell less negative and allow Cl^- to leave the cell, offsetting the effect of Na⁺.
C) decreases the probability of the postsynaptic cell reaching threshold since the entry of Na⁺ into the cell (through another route) will make the cell less negative and Cl^- will enter the cell, offsetting the depolarizing effect of Na⁺.
D) none of these.