You used a default gateway of 192.168.11.10 for network B at the beginning but you later used 192.168.11.0 while doing routing, is that meant to be a mistake?
Very informative brotha. Can you do 6 networks with 3 routers next pls? It goes like this: 6PCs 6switches 3Routers For ex: pc 0 and 1 w/ Lan 1 and 2 connected to HQ, like that