Possibility (6)
'possibility' is the definition.
(I know that room is a type of chance)
This is all the clue.
(Other definitions for room that I've seen before include "kitchen?" , "See 17" , "Space within a building" , "Space; chamber" , "Space, area" .)
'possibility' is the definition.
(chance is a kind of possibility)
This is the entire clue.
(Other definitions for chance that I've seen before include "Risk the fortune" , "Serendipity" , "Risk the opportunity" , "Odds" , "Luck -a fine thing?" .)
'possibility' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for option that I've seen before include "possibility" , "Possible choice" , "Preference" , "Alternative for choice" , "Right to choose" .)