单项选择题YourCustomerhas21users,eachrequiringbothPCandIPPhoneconnectivity.Whichisthecorrectconfigurationforthiscustomer?()
A.1 Cisco 2811 ISR,1 Catalyst Express 500G-12TC,2 Catalyst Express 500-24PC
B.1 Cisco 2851 ISR, Catalyst Express 500G-12TC,3 catalyst Express 500-24PC
C.1 Cisco 2821 ISR,Catalyst Express 500G-12TC,2 Catalyst Express 500-24PC
D.1 Cisco 2801 ISR,1 Catalyst Express 500-24PC