Which wiring system would you use in small structures where the main need is for lighting?

The selection of a two-wire, single-phase wiring system in small structures primarily for lighting is an appropriate choice because this type of system is cost-effective and sufficient for low-power applications like general lighting. A two-wire system consists of one hot wire and one neutral wire, which allows for the safe delivery of electrical power to lighting fixtures without the additional complexity or cost associated with more robust systems.

This configuration is typically used in residential or small commercial settings where the demand for power is modest, and the simplicity of the system aids in easier installation and maintenance. The two-wire system provides adequate voltage supply for standard light fixtures and is in compliance with electrical codes for these types of small structures.

In contrast, three-phase systems like those mentioned in the other choices are designed for higher power loads and would not be necessary or practical for simple lighting needs. Three-phase systems allow for more efficient power distribution and are generally used in industrial applications where heavy machinery requires significant electrical power. Therefore, the context of small structures with a focus on lighting makes the two-wire, single-phase system the most logical and effective choice.