Why is the performance different between the two buckets?

A company has recently implemented ECS EX500 nodes for two in-house applications. There is a defined bucket for the data of each application. The storage administration team is receiving complaints about the performance difference in the two applications.

Why is the performance different between the two buckets?
A . One bucket is using flash drives, and the other bucket is using SATA drives.
B . Neither bucket is using a load balancer.
C . One bucket is configured with a load balancer, and the other bucket has no load balancer.
D . One bucket is using NFS, and the other bucket is using S3.

Answer: D