In Amazon EC2 Container Service components, what is the name of a logical grouping of container instances on which you can place tasks?

In Amazon EC2 Container Service components, what is the name of a logical grouping of container instances on which you can place tasks?
A . A cluster
B . A container instance
C . A container
D . A task definition

Answer: A

Explanation:

Amazon ECS contains the following components:

A Cluster is a logical grouping of container instances that you can place tasks on.

A Container instance is an Amazon EC2 instance that is running the Amazon ECS agent and has been registered into a cluster.

A Task definition is a description of an application that contains one or more container definitions.

A Scheduler is the method used for placing tasks on container instances.

A Service is an Amazon ECS service that allows you to run and maintain a specified number of instances of a task definition simultaneously.

A Task is an instantiation of a task definition that is running on a container instance.

A Container is a Linux container that was created as part of a task.

Reference: http://docs.aws.amazon.com/AmazonECS/latest/developerguide/Welcome.html