What type of receptacle is included in the smallest box assembly with specified wiring?

The single receptacle is included in the smallest box assembly with specified wiring because it requires the least amount of space compared to the other types of receptacles listed. A single receptacle only accommodates one plug, which means that the box can be compactly sized to fit the wiring and device.

In contrast, a double receptacle is designed to accommodate two plugs, meaning it needs a larger box to house the additional wiring and connections. A ground fault circuit interrupter (GFCI) receptacle, while also potentially fitting into a standard box, often requires more space due to its internal mechanisms designed for safety and protection against electrical shock. Lastly, a rough-in receptacle is typically used during the installation process and might not refer specifically to a finalized device needing permanent wiring, adding further complexity to its box assembly requirements.

Overall, the single receptacle is the simplest and most space-efficient option, making it the correct answer in this context.