Hackers are sending calls through a gateway router that is running SIP. The engineer blocks all SIP messages to the router except from their SIP server, which has an IP address of 208.177.10.1. The customer also must connect via SIP to their Cisco Expressway server with an IP address of 10.1.10.110. Which series of commands secures the router from the hackers?
A. voice service voip voip security allow ipv4 208.177.10.1 255.255.255.255 ipv4 10.1.10.110 255.255.255.255
B. voice service voip ip address trusted list ipv4 208.177.10.1 255.255.255.255 ipv4 10.1.10.110 255.255.255.255
C. voice service voip allow-connections sip to sip ipv4 208.177.10.1 255.255.255.255 ipv4 10.1.10.110 255.255.255.255
D. voice service voip address-hiding ipv4 208.177.10.1 255.255.255.255 ipv4 10.1.10.110 255.255.255.255
