The internal dimension of a room is 10m 10m 4m (height). The total area of the doors and windows are 16 m2. Keeping the doors and windows closed, the reverberation time of the room becomes 1.2 second. Assume all the interior surfaces including doors and windows have some absorption coefficient. If all doors and windows of the room are kept fully open, the reverberation time will be _____ second (rounded of to one decimal place).

• A. 3.23
• B. 1.26
• C. 12.6
• D. None of the above