A coffee shop wants to offer free Wi-Fi but also display a QR code on the menu so customers can join without typing a password. What Wi-Fi provisioning mechanism does scanning a Wi-Fi QR code use, and what is encoded in the QR code?

• A.A Wi-Fi QR code encodes a URL that opens a captive portal registration page where the user creates an account; 802.11ac operates exclusively in the 2.4 GHz band to maximize wall penetration. The hidden node problem is solved by lowering the AP's beacon interval
• B.A Wi-Fi QR code contains the access point's WPS PIN, which the device uses to complete WPS PIN exchange
• C.A Wi-Fi QR code encodes a standardized string containing the SSID, security type (WPA/WEP/nopass), and password (e.g., WIFI:T:WPA;S:CoffeeShop;P:Welcome123;;) - the operating system parses this string and automatically connects without user typing