If the customer believes that the performance of the cluster is too slow, which of the following questions are NOT immediately needed to begin troubleshooting the issue?

A.
Which benchmarks are being used to measure the performance?

B.
What is the expected performance level?

C.
Is the cluster using dual InfiniBand?

D.
Are all clients having this issue or just a few?

E.
How are the clients trying to connect?