Unsubscribe, with "out" (3)

I believe the answer is:
opt
(Other definitions for opt that I've seen before include "Pick from pot" , "Have preference for something" , "Choose from pot" , "Make a choice" , "Select as a preferable alternative" .)
I believe the answer is:
opt
(Other definitions for opt that I've seen before include "Pick from pot" , "Have preference for something" , "Choose from pot" , "Make a choice" , "Select as a preferable alternative" .)