__ for (decide upon) (3)
I believe the answer is:
opt
'for decide upon' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for opt that I've seen before include "Select as a preferable alternative" , "Decide between possibilities, choose" , "Make a choice" , "Choose from pot" , "Hold in the highest esteem" .)