Narrowed 8 3/4 questions

Thinking it's a cone.
i was thinking "cone no thrust button" but ive been mistaken more than once today.

I may have to try harder on this dropout. It looks like there is a dimple in there (where the button is located) and it looks like there is a round circle around the dimple.....so maybe its sheared off? How hard should I try is the question or say .....meh.