多项选择题 Which two are elements of the operational-efficiency business challenge?（）

单项选择题 Identity authentication, protocol encryption, secure guest access, voice over WLAN features, and a small device footprint are all highlights of what product in the wireless technology market?（）

单项选择题 Increased productivity, minimized legal risks, and improvements in "green" operation can be easily linked to Cisco solutions in which technology area?（）