What is a placement group?
A.
A collection of Auto Scaling groups in the same region
B.
A feature that enables EC2 instances to interact with each other via high bandwidth, low latency connections
C.
A collection of authorized CloudFront edge locations for a distribution
D.
A collection of Elastic Load Balancers in the same Region or Availability Zone
Explanation:
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html