How is a branch circuit typically protected?

A branch circuit is typically protected using a circuit breaker or a fuse, which serve to safeguard the circuit from overloads and short circuits. Circuit breakers can be reset after an overload or fault condition, while fuses must be replaced once they have blown. This approach ensures that the electrical system does not become a fire hazard or cause damage to the wiring and connected devices.

Using only a fuse would not encompass the full range of options available for branch circuit protection, as circuit breakers are also an essential method of protection today. A transformer is not a protective device; instead, it is used for adjusting voltage levels. Circuit tracking is not a recognized method for protecting branch circuits under the NEC, so it does not apply in this context. Thus, the most accurate and comprehensive answer is the option that includes both circuit breakers and fuses as means of protection for branch circuits.