How would you configure a static EtherChannel?

To configure a static EtherChannel, you use the command that specifies the channel group number and sets the mode to "on." The "channel-group 1 mode on" command creates a static EtherChannel by forcing the interfaces into an EtherChannel without any negotiation. This mode is useful for ensuring that the links are always bundled together regardless of the status of either end, thus providing a consistent link aggregation.

The other options would not create a static EtherChannel as effectively. The notion of "interface mode static" does not directly correspond to valid configuration commands within Cisco IOS. Similarly, "set etherchannel static" is not a recognized command structure in Cisco devices, which typically utilize the channel-group command format. The "etherchannel 1 mode active" phrase suggests a mode that would engage the Link Aggregation Control Protocol (LACP), which is dynamic and not static. Therefore, the correct approach for configuring a static EtherChannel is indeed through the specified channel-group configuration outlined in the correct answer.