Why Is It Critical That the K+ Channel Activation Gate

Why is it critical that the K+ channel activation gate responds slightly more slowly to depolarization than the Na+ channel activation gate?

A) If they showed identical response times, movements of Na+ and K+ ions would cancel out each other's effects on membrane potential changes.
B) If they showed identical response times, movements of Na+ and K+ ions would magnify each other's effects on membrane potential changes, creating dangerously large action potentials.
C) It is not critical and there would be no change in action potential characteristics if this difference in response time did not exist.