Which of the following cannot be used in Amazon EC2 to control who has access to specific Amazon EC2instances?
A.
Security Groups
B.
IAM System
C.
SSH keys
D.
Windows passwords
Explanation:
http://blogs.aws.amazon.com/security/post/Tx29HCT3ABL7LP3/Resource-level-Permissions-for-EC2-
Controlling- Management-Access-on-Specific-Ins
A seems to be the most logical answer.
The question asked “who” as in users. B, C and D are associated with users. Security groups act as a virtual firewall that controls the traffic for one or more instances. . In addition, the URL posted in the answer “http://blogs.aws.amazon.com/security/post/Tx29HCT3ABL7LP3/Resource-level-Permissions-for-EC2-Controlling-Management-Access-on-Specific-Ins” stated “Customers have been able to use IAM policies to control which of their users or groups could start, stop, reboot, and terminate instances across all EC2 instances under an account.”