It's been a long time since I've done RAF, so I'm not 100% sure on this, so you may want to wait on someone who's done it recently.

When you create the other accounts, they are all in a list under the same BattleNet. So, under your current BattleNet, you log in, select the main account {WOW1} from the list on the right in the account summery page. Go to Referrals and Rewards. Send out invites to the B and D accounts.

Once those accounts are set up, they will show up under the main account management page in the list on the right. Select account B and got to Referrals and Rewards and send a RAF invite to C. Go back to the main account summery page and do the same thing for D to E.

You may have to wait for the accounts to fully upgrade, which can take 72 hours.