When is the use of armored cable (AC) permitted?

The use of armored cable (AC) is permitted when additional physical protection is required for the conductors. This type of cable provides a degree of mechanical protection due to its metal armor, making it suitable for areas where conductors might be subject to physical damage. The metal sheath helps safeguard the inner conductors from impacts, abrasion, and other potential hazards, thereby enhancing the overall durability and safety of the electrical installation.

In specific applications, such as in locations not easily accessible or where the risk of damage is higher, using armored cable is not only favored but sometimes mandated by the National Electrical Code (NEC) for safety considerations. This aspect reinforces the necessity of using AC in contexts where standard non-armored cables may not provide sufficient protection.

The other choices imply limitations or conditions that do not align with the flexible deployment of armored cable, making option B the most appropriate and comprehensive.