Refer to the exhibit. EIGRP has been configured on routers R1 and R2. However, R1 does not show R2 as a neighbor and does not accept routing updates from R2.<br /> What could be the cause of the problem?()<br /> <img src="https://nimg.ppkao.com/2018-07/ppweb/2018073014311283755.png?sign=d3373c3a523bdbb1747b6a083e943cd0&t=62d2bc1c" />
A、The no auto - summary command has not been issued under the EIGRP process on both routers.
B、Interface E0 on router R1 has not been configured with a secondary IP address of 10.1.2.1/24.
C、EIGRP cannot exchange routing updates with a neighbor's router interface that is configured with tw o IP addresses.
D、EIGRP cannot form neighbor relationship and exchange routing updates with a secondary address.