When a Demisto Engine is part of a Load-Balancing group it?

Must be in a Load-Balancing group with at least another 3 members

It must have port 443 open to allow the Demisto Server to establish a connection

Can be used separately as an engine, only if connected to the Demisto Server directly

Cannot be used separately and does not appear in the in the engines drop-down menu when configuring an integration instance