The integrated services routing architecture provides the performance， availability， and reliabilityneeded to scale mission-critical business applications in the most demanding environments.Which statement best describes the benefits of Cisco Integrated Services Routers？（）

A. ISRs provide threat defense against attacks from hackers and viruses that can occur in thenetwork.
B. ISRs provide the framework to integrate and extend wired and wireless networks
C. ISRs provide concurrent security， voice， data， wireless， and application optimization services.
D. ISRS provide the common fabric， functionality， and CLI across the network.