Networks

I don't think that this has to do with EIGRP.

Routers have to have a common network to transfer data. When directly connected they will find eachother without a routing protocal at all. You can verify this by looking at your ip routing table. The routers should have each other mapped like this.

C 192.168.10.12/29 is directly connected to Ethernet 0

If the routers are directly connected there should be an entry in both routers like that. If this is the way you have them, then check your config on B. If you post both your config's we can help determine what's going on.

Can you ping from the LAN or the WAN interface. Check status' interfaces on router B