Answer:
Among the options provided, strontium hydroxide (Sr(OH)₂) is a strong base. It is one of the eight common strong bases that completely dissociate in solution, similar to other strong bases like sodium hydroxide (NaOH) and potassium hydroxide (KOH).
The other options—HClO (hypochlorous acid), HF (hydrofluoric acid), and H₃P (phosphoric acid)—are not classified as strong bases.