How does ECS work with a Hadoop MapReduce job?

How does ECS work with a Hadoop MapReduce job?
A . ECS works with the Hadoop cluster to move data in the most efficient possible way
B . ECS runs MapReduce jobs on the ECS nodes
C . ECS is a client for Hadoop MapReduce
D . ECS can be analyzed using MapReduce without requiring movement of the data

Answer: D