Which statement best describes the Cisco 2700 Location Appliance collection of location information for wireless devices?（）

• A、all Wi-Fi devices on the WLAN send directly received signal strength indication （RSSI） information to the Cisco Wireless Location Appliance through SNMP
• B、an AP collects RSSI information which is forwarded to wireless controllers through LWAPP. Wireless controllers forward aggregated RSSI to the location appliance through SNMP
• C、the APs collect received signal strength indication （RSSI） information from all Wi-Fi devices and forward the information to the Cisco Wireless Location Appliance through the LWAPP
• D、the Cisco WLAN controllers bypass the received signal strength indication （RSSI） information from all Wi-Fi devices to the Cisco Wireless Location Appliance through the LWAPP