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