Final answer:
When a circuit breaker trips, it should be turned off, then reset after addressing the cause of the trip. This process allows the circuit breaker to resume protecting the electrical circuit from overload or short circuit.
Step-by-step explanation:
When a circuit breaker trips, it is typically necessary to reset it once you have addressed the reason for the trip. This is because a circuit breaker is designed as an automatic but restorable electric switch that protects electrical circuits from damage caused by excess current from an overload or short circuit. Its basic function is to interrupt current flow after a fault is detected. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation.
Therefore, in response to the choice provided, you don't have to 'Leave, unattended' or 'Call an electrician' for a circuit breaker that trips. The correct approach would be to 'Turn off, then reset' the circuit breaker, option (b), assuming you have taken necessary safety checks and the issue that caused the tripping has been resolved.