A cylindrical drum of diameter 1.25 meters is securely held in position in an open channel of rectangular section. The channel is 3 meters wide and the flow is 6.9 m³/s. The water flows under the drum. What is the discharge through the channel?

A) 20.7 m³/s
B) 23.0 m³/s
C) 27.6 m³/s
D) 31.2 m³/s