OS X or OS 10: The Answer Is Built Into Your Mac

Many IT professionals know OS X stands for Operating System 10. But if you know anyone that thinks it is OS “ex,” you can prove to them the correct pronunciation using a simple command built into every Mac.
Just type this into Terminal (it is case-sensitive, as you will see)
say OS X
Your Mac will verbally say “OS Ten.”
if you instead type in:
say OS x
(notice the lowercase “x”)? Your mac will say “OS ex.” Thanks Apple programmers for your attention to detail.
Now if only such proof existed for GIFs…