Why are five HDMI output options displayed when there is just one HDMI port on my NUC? Just curious.

Why are five HDMI output options displayed when there is just one HDMI port on my NUC? Just curious.

Yep its a common thing. My non NuC is the same no idea why though.
Display port often has an HDMI inside that can be exposed with an adapter, thunderbolt can have 2 or more.
You can disable HDMI Audio in the BIOS if it bothers you, I have done this with mine - the setting is not difficult to find, and the audio device menu looks much cleaner afterwards.