Water flows at 36 m³/s in a rectangular channel of width 10 m and Manning's n of 0.030. If the depth of flow at a channel section is 3 m and the slope of the channel is 0.001, classify the water-surface profile. What is the slope of the water surface at the observed section? Would the water-surface profile be much different if the depth of flow were equal to 2 m?
A) Mild slope, 0.003, Yes
B) Steep slope, 0.003, No
C) Mild slope, 0.0036, Yes
D) Steep slope, 0.0036, No