Briefing Amazon Knowledge

what does it do?

If I write the below command, what does it do?
ec2-run ami-e3a5408a -n 20 -g appserver

A.
Start twenty instances as members of appserver group.

B.
Creates 20 rules in the security group named appserver

C.
Terminate twenty instances as members of appserver group.

D.
Start 20 security groups