Among the substances listed, water has the highest boiling point.
- Water (H₂O) boils at 100°C (212°F) at standard atmospheric pressure.
- Nitrogen (N₂) boils at -196°C (-321°F).
- Hydrogen sulfide (H₂S) boils at -60°C (-76°F).
- Ammonia (NH₃) boils at -33°C (-28°F).
Therefore, the correct response is water.