A conference room with dimensions 4 m by 10 m by 20 m is filled with 100 conference attendees. The air-conditioning system fails, resulting in an increasing temperature. There are 50 100-watt light bulbs, and each person emits approximately 400 Btu/hr (0.117 kJ/s). Assuming a constant pressure, in 15 minutes the temperature will rise approximately:
(A) 10°C
(B) 14°C
(C) 18°C
(D) 22°C