option key stuck (not physically)

This started this morning for me on a macbook pro in the middle of working on the computer. I searched and tried several things, coming close to losing my mind in the process. I know this is an old thread, but its the first one that comes up on google and I finally got it fixed and wanted to share what worked for me in case anyone else is hunting for a solution...

My symptoms -

Keystrokes and trackpad were all of the sudden being modified as if the option key was being pressed.

Keyboard viewer did not show that the option key was being pressed.

Tried disabling option key in modifier key controls

Tried rebooting - no change

Bluetooth keyboard worked normally

Sticky keys was turned off

My fix-

Open system preferences

Select accessibility

Select keyboard

Enable sticky keys

Press option twice quickly to enable sticky and once more to turn it off (option key must be enabled if you previously disabled it in modifier key controls)

Problem solved!

Turned sticky keys back off afterwards

Somehow the laptop had a sticky option input (even though sticky keys was off and it was not displayed in the top right corner) and activating/deactivating the sticky option key cleared it.