A frictionless piston-cylinder based enclosure contains some amount of gas at a pressure of 400 kPa. Then heat is transferred to the gas

Q: A frictionless piston-cylinder based enclosure contains some amount of gas at a pressure of 400 kPa. Then heat is transferred to the gas at constant pressure in a quasi-static process. The piston moves up slowly through a height of 10 cm. If the piston has a cross-section area of 0.3 m2, the work done by the gas in this process is

(a) 6 kJ

(b) 12 kJ

(c) 7.5 kJ

(d) 24 kJ