A ground-fault protection device for photovoltaic systems must be capable of which of the following?

A ground-fault protection device for photovoltaic systems must be capable of detecting a ground-fault current because its primary function is to identify any unintended current paths to the ground that could result from insulation failures or other faults in the electrical system. Ground faults can pose significant safety risks, including electrical shock and fire hazards, and can also damage equipment. By detecting ground-fault current, the device ensures that appropriate protective actions can be taken, such as disconnecting the affected circuit and preventing further damage or hazards.

The other options do not align with the primary function of ground-fault protection. Providing direct electrical connection is more characteristic of circuit components that facilitate power flow rather than protective devices. Monitoring temperature fluctuations and regulating voltage levels pertain to different parameters in electrical systems and are not the core function of ground-fault protection devices.