An Otto cycle takes in air at a temperature of 20°C and a pressure of 100 kPa. The high temperature is 1000°C and the compression ratio is 8. The specific heat for air at constant pressure is 1.00 kJ/kg K, and the specific heat for air at constant volume is 0.716 kJ/kg-K. The mass of air in a cylinder is 0.002 kg. If the specific heats stay constant, the clearance volume is most nearly : (A) 90 cm
(B) 120 cm3
(C) 180 cm
(D) 210 cm