Why would an administrator change the value of the spanning-tree priority of a switch?（）

• A、in order to optimize the path that frames take from source to destination
• B、to increase the priority so a designated port will become a root port
• C、to increase the BID, so the switch is more likely to become root bridge
• D、in order to allow VLANs to be sent from one switch to another across a single link
• E、to force a given switch to become an STP server