Cisco Unified Communications 500 Series for Small Business， a critical part of the Cisco SmartBusiness Communications System， is a unified communications solution for small businesses that provides voice， data， voicemail. For which technology the Cisco UC520 provides integrated WLAN connectivity to mobile clients？（）

A. distributed routing
B. Cisco Unity Express
C. security， firewall and VPN
D. analog devices

A. A Cisco Integrated Security Solution uses the Cisco UN to form a layered and integratednetwork of protection that enables the enforcement of security policies throughout theinfrastructure.
B. A Cisco Integrated Security Solution provides software tools that allow customers to centrallymanage their network security policies.
C. in contrast to point products， the Cisco SDN is a system of defense that leverages the ubiquitous sensing and control capabilities of the network. Each part communicates with the otherto strengthen protection across the entire infrastructure.
D. A Cisco Integrated Security Solution enables barriers that serve as both physical and virtualprotection against possible threats. Security barriers include firewalls， authentication products，access control products， and tunneling and encryption techniques.

A. Enhanced Image
B. StandardImag
C. Cisco IOS software
D. Enhanced Multilayer Software Image