On which systems is Quality of Service available?

A.
Physical Unity systems only

B.
UnityVSA systems only

C.
Physical Unity and UnityVSA systems

D.
All Flash Unity systems only

Explanation:
UnitVSA features Host I/O limits, also known as Quality of service.
The EMC [Physical] Unity array comes with a pack of new hardware and software features focusing on the true
unification:
Support for setting up Host I/O limits, also known as QOS, providing a more predictable performance for the
workloads by putting limits on I/O throughputs and bandwidth
DPE reduced from a 7U footprint to an innovative 2U footprint
12 GB SAS back-end for the Unity DAEs; EMC VNX/VNXe supported only 6 GB SAS backend
Completely redesigned user interface based on HTML5
https://www.emc.com/collateral/white-papers/h15092-emc-unity-unity-vsa.pdf (page 16)
http://www.presidio.com/blog/technical-summary-emc-unification-unity