Ann, a security administrator, has concerns regarding her company's wireless network. The network is open and available for visiting prospective clients in the conference room, but she notices that many more devices are connecting to the network than should be. Which of the following would BEST alleviate Ann's concerns with minimum disturbance of current functionality for clients?
A. Enable MAC filtering on the wireless access point.
B. Configure WPA2 encryption on the wireless access point.
C. Lower the antenna's broadcasting power.
D. Disable SSID broadcasting.