Which of the below mentioned statements is true with respect to the placement group?

A user has launched 10 EC2 instances inside a placement group.

Which of the below mentioned statements is true with respect to the placement group?
A . All instances must be in the same AZ
B . All instances can be across multiple regions
C . The placement group cannot have more than 5 instances
D . All instances must be in the same region

Answer: A

Explanation:

A placement group is a logical grouping of EC2 instances within a single Availability Zone. Using placement groups enables applications to participate in a low-latency, 10 Gbps network. Placement groups are recommended for applications that benefit from low network latency, high network throughput or both.

Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html