Assuming a Cluster Running HDFS, MapReduce Version 2 (MRv2) on YARN

Multiple Choice

Assuming a cluster running HDFS, MapReduce version 2 (MRv2) on YARN with all settings at their default, what do you need to do when adding a new slave node to cluster?

A) Nothing, other than ensuring that the DNS (or/etc/hosts files on all machines) contains any entry for the new node.
B) Restart the NameNode and ResourceManager daemons and resubmit any running jobs.
C) Add a new entry to /etc/nodes on the NameNode host.
D) Restart the NameNode of dfs.number.of.nodes in hdfs-site.xml