Briefing Amazon Knowledge

What does the following command do with respect to the …

What does the following command do with respect to the Amazon EC2 security groups?
ec2-revoke RevokeSecurityGroupIngress

A.
Removes one or more security groups from a rule.

B.
Removes one or more security groups from an Amazon EC2 instance.

C.
Removes one or more rules from a security group.

D.
Removes a security group from our account.