Which of the following protects against overcurrent in a circuit?

The choice indicating that disconnect switches and circuit breakers protect against overcurrent is correct because both devices are designed specifically to interrupt the flow of electrical current when it exceeds a predetermined level. Circuit breakers function by sensing overcurrent conditions and automatically tripping to open the circuit, thereby preventing potential damage to equipment and reducing fire hazards. Disconnect switches, while primarily used for isolating circuits for maintenance, can also be integrated with circuit breakers to ensure safe operation.

Fuses, while they do provide overcurrent protection, are not exclusively identified as the primary device in this choice, as the question encompasses various protection methods. Surge arresters and lightning rods are primarily designed for protection against voltage surges caused by lightning or transient voltages, not necessarily for overcurrent. Motor starters serve to protect motors from overcurrent conditions but are not comprehensive protection devices across the entire circuit. Therefore, the combination of disconnect switches and circuit breakers reflects a wider range of functionality concerning overcurrent protection in electrical systems.