A cafeteria is facing lawsuits related to criminal internet access that was made over its guest network. The marketing team, however, insists on keeping the cafeteria's phone number as the wireless passphrase. Which of the following actions would improve wireless security while accommodating the marketing team and accepting the terms of use?
A. Setting WLAN security to use EAP-TLS
B. Deploying a captive portal for user authentication
C. Using geofencing to limit the area covered by the WLAN
D. Configuring guest network isolation