Final answer:
Using standard fuses and circuit breakers that allow a motor to start up can lead to overcurrent, damaging the motor because they might not tolerate the sustained high startup current.
Step-by-step explanation:
The danger of using standard fuses and circuit breakers that allow a motor to start up is b) Overcurrent can damage the motor. Electric motors often draw a higher current when starting up compared to their normal operating current. While most fuses and circuit breakers are designed to tolerate high currents briefly, electric motors may sustain these higher currents for several seconds, which could potentially lead to overcurrent that damages the motor unless special 'slow blow' fuses or appropriate circuit breakers are used to accommodate this startup behavior.