Why does my MacBook Air show as an audio option on iPhone's Phone app?

On my iPhone in the Phone app I open a contact and select a phone number. The Phone app has six buttons, one is Audio. If I click Audio is shows iPhone, Speaker, and MacBook Air.

Why?

Why does it show MacBook Air on this list? How do I get rid of it?

I've looked at settings on both the iPhone and the MacBook Air, and none of them indicate that the computer should show on this list on the iPhone.

The computer does not have the iPhone listed in System Settings->Sound->Output & Input.

System Preferences > General > AirDrop & Handoff > "Allow Handoff between this Mac and your iCloud

devices" is already disabled.

Calls on Other Device > Allow Calls on Other Devices is not turned on.

FaceTime > Preferences > Settings > Calls from iPhone is not on.

Settings > General > AirPlay & Handoff does not exist on my iPhone. However,

Settings > General > AirPlay & Continuity does. On that screen, "Continuity Camera" is turned off. None of the settings on AirPlay & Continuity are turned on.

This situation is dysfunctional because when I make a call, the fact that there are three items on the context menu means that I have to press the Audio button and then pick one, whereas if the computer is not on this list, the phone will go to the Speaker just from pressing the Audio button.

How do I remove MacBook Air from this context menu?

[Re-Titled by Moderator]