A balloon behaves such that pressure inside it is proportional to the diameter squared. It contains 2kg of ammonia at 0°C, 60% quality. They are now heated so that the final pressure is 600 kPa. Find the work done in the process.

• A. 117.5 kJ
• B. 127.5 kJ
• C. 137.5 kJ
• D. 147.5 kJ