FULL - ?
If 1, ?U?? is proved by FISH = 0 = HELL.
If 0, ??M? is proved by DUMB = 1 = DUMP (disproving P/B as last) and DUMP = 1 = PUMP (disproving D/P as first) and FULL disproving U as second while DUMP, PUMP, and DUMB all score 1.
EDIT: Miscoloured the U and M.