Enterprise Router R1, in ASN 1, connects to ISP Router I1, ASN 2, using eBGP. The single serial link b etween the two routers uses IP addresses 10.1.1.1 and 10.1.1.2, respectively. Both routers use their S0/0 interfaces for this link. Which of the following commands would be needed on R1 to configure eBGP?（）

• A、router bgp 2
• B、router bgp 1
• C、neighbor 10.1 .1.2 remote - as 2
• D、neighbor 10.1.1.2 Update - source 10.1.1.1
• E、neighbor 10.1.1.2 Update- source S0/0