When configuring vPC-HM CDP with multiple links to the same switch， are port-channels required？（）
- A Each link between the upstream switch and the VEM is an individual subgroup.
- B Connections that go to the same upstream switch must be configured with the command channel-group mode active.
- C Connections that go to the same upstream switch must be configured with the command channel-group mode passive.
- D With vPC-HM CDP， the user can pin traffic from a specific VM to a specific uplink.
- E Connections that go to the same upstream switch must be configured with the command channel-group mode on.