Zeroth law of thermodynamics is not valid for the following:

• A. 50 ml of water at 25°C is mixed with 150 ml of water at 25°C
• B. 500 ml milk at 15°C is mixed with 100 ml of water at 15°C
• C. 5 kg of wet steam at 100°C is mixed with 50 kg of dry and saturated steam.
• D. 10 ml of water at 20°C is mixed with 10 ml of sulphuric acid at 20°C