Correct Answer : rs.reconfig()
Explanation : To reconfigure an existing replica set, first retrieve the current configuration with rs.conf(), modify the configuration document as needed, and then pass the modified document to rs.reconfig().
Correct Answer : sh.disableBalancing()
Explanation : sh.disableBalancing() does not affect balancing of other collections in a sharded cluster.
Correct Answer : sh.getBalancerHost()
Explanation : sh.enableSharding() enables sharding on a specific database.
Correct Answer : sh.getBalancerState()
Explanation : sh.getBalancerState() returns true when the balancer is enabled and false if the balancer is disabled.