They have a higher density of voltage-gated Na+ channels per unit of membrane surface

APs have to be produced less often because there is less leakage of electrotonic current flow

APs have to be produced less often because they use unsalted conduction

APs are produced more often because of the lower leakage of electrotonic current so that CV is faster

They have more voltage-gated Na⁺ channels per unit of membrane surface