Which type of electrical wire can be buried if kept moisture-free?

The correct answer is EMT, which stands for Electrical Metallic Tubing. This type of conduit is typically used to protect and route electrical wiring. EMT can indeed be buried as long as it is installed in a manner that keeps moisture away from the electrical conductors inside. The metal tubing provides a durable barrier that can withstand the pressures and potential moisture that can occur when buried underground.

In contrast, non-metallic sheathed cable, also known as Romex, is designed primarily for above-ground uses or specific conditions where moisture exposure is minimal. While it has insulation, it is typically not rated for direct burial unless it is specifically designed for that use.

Though thermoplastic conductors are often water-resistant, they are generally not suitable for burial without additional protective measures. BX, or armored cable, can provide some moisture resistance due to its metal cladding, but it is also primarily intended for above-ground installations and may not be the best option for burial in all environments.

Thus, EMT stands out as the appropriate choice for buried applications when kept moisture-free, as its durable structure provides the necessary protection against potential underground conditions.