Which control method uses a wireless one-way interface to operate a single AV device?

Infrared is a control method that utilizes a wireless one-way interface to operate a single AV device. It utilizes light waves in the infrared spectrum, which are emitted by an infrared transmitter and received by an infrared receiver on the AV device. Because infrared signals do not pass through solid objects effectively, this method is typically used within a direct line of sight, allowing for simple operation of devices such as televisions, DVD players, and other consumer electronics.

The other options involve different methods of communication or control. Bluetooth is a two-way communication technology that allows for bidirectional data exchange between devices, making it unsuitable for a one-way control scenario. RF control employs radio frequency signals, which can be one-way or two-way but typically supports more complex communication for multiple devices rather than being limited to a single device. Wi-Fi Direct also facilitates two-way communication between devices over a Wi-Fi connection, allowing for more data-intensive applications. All of these characteristics distinguish infrared as the correct answer.