12. A cylinder contains 1.2 moles of ideal gas, initially at a temperature of 116℃. The cylinder is provided with a frictionless piston, which maintains a constant pressure of 6.4 x 105 Pa on the gas. The gas is cooled until its temperature has decreased to 27℃. For the gas Cy= 11.65 J/molㆍK, and the ideal gas constant R = 8.314 J/mol.K. (A) The work done by the gas during this process is 890 J. (B) The work done on the gas during this process is 890 J. (C) The change in the internal (thermal) energy of the gas during this process is +1200 J. (D) The heat transferred from the gas during this process is -1200 J. (E) The heat transferred to the gas during this process is +2100 J.