Which type of cable is permitted to be buried in a trench underground covered with stabilized sand?

The correct choice is Type MI cable, which stands for Mineral Insulated cable. This type of cable is specifically designed to withstand harsh environments and can be buried directly in the ground, including in stabilized sand. The construction of MI cable allows it to be insulated with a mineral like magnesium oxide, making it highly durable and resistant to moisture, corrosion, and physical damage, which qualifies it for underground installations.

Type NM (Non-Metallic Sheathed) cable is typically not suitable for underground burial unless it is protected within a conduit, as it is primarily intended for indoor residential use. Type UF (Underground Feeder) cable is specifically designed for underground use but may not be suited for certain soil conditions without additional protection. Type SE (Service Entrance) cable is meant for above-ground applications and is installed as part of the electrical service to a building, not for direct burial.

Understanding the specific applications and permitted locations for each type of cable is crucial for ensuring safety and compliance with electrical codes.