Circuit breakers must generally be...

Circuit breakers must generally be readily accessible to ensure that they can be quickly and easily reached in the event of an electrical issue, such as a fault or overload that may require immediate attention. This accessibility is crucial for safety purposes, as it allows individuals to turn off power to affected circuits without delay in emergency situations. Regulatory codes, like the National Electrical Code (NEC), often stipulate that circuit breakers should be located in a way that allows safe and unhindered access.

The other choices do not align with this requirement. Concealed circuit breakers may pose a safety hazard since they cannot be quickly accessed. Locking away breaker's would significantly delay action needed to address electrical issues. While being wall-mounted can be a common installation method, it does not inherently guarantee accessibility unless appropriately positioned for easy access.