A computer connects to a wired network but cannot detect wireless networks. Which component may be missing?

Correct answer: Wireless network adapter

The governing concept is that different network media require suitable hardware interfaces. A wired connection can work through Ethernet hardware, but detecting Wi-Fi networks requires a wireless network adapter, together with its driver and antenna. Therefore, option B is correct. An optical drive reads discs, a sound card handles audio, and a printer driver supports printing; none of these scans for wireless networks.