Etherchannel and root bridge Sim

[muddytechz]

My question would be for Task #2.  To ensure that Sw10 is always the root bridge.  Wouldn't you use priority of 0?  If you just use root primary then if another siwtch is added with a lower priority then it would take over.  Setting root primary only calculates for existing switches in topology.  

I should be able to find information to back this up if needed.