B. Probe

Before associating with an AP, a STA (Station or Wireless Client) broadcasts a Probe Request frame to discover available wireless networks in the area. This frame can contain a specific SSID or be a broadcast to discover all available SSIDs.

The AP then responds with a Probe Response frame, which includes information about the network, such as the SSID, BSSID, supported data rates, and other network parameters.

Based on the received Probe Responses, the STA can select a suitable network and initiate the association process.