Air in a Room of Dimensions 3 M × 4

Air in a room of dimensions 3 m × 4 m × 2 m is being heated by the Sun shining perpendicularly through a window of area 2 m², from a temperature of 10°C to 20°C in a time of 2 hours. Given that sunlight emits radiation with a total intensity of 1.361 kW/m², and assuming a pressure of 1 atm and that the mass of air in the room is constant, what fraction of this energy is absorbed by the air, thus warming up the room?

A) 2.2 × 10^-3
B) 3.3 × 10^-3
C) 6.7 × 10^-3
D) 1.1 × 10^-2