The network administrator wants to enable an EtherChannel between two switches in "on" mode. The administrator connects the cables and enables the interfaces， but while configuring the EtherChannel in the first switch， a spanning-tree loop was detected. Which two of these procedures can avoid this problem？（）
- AConfigure the EtherChannel as "desirable" first.
- BAssign all interfaces to the same VLAN.
- CDisable PortFast on the interfaces in the EtherChannels.
- DDisable all interfaces first.
- EFast Ethernet and Gigabit Ethernet ports cannot be assigned to the same EtherChannel.
- FFix cabling problems.