Which statement best defines Manning's equation and its use in civil hydraulics?

Which statement best defines Manning's equation and its use in civil hydraulics?

• A. Q = V × A; used to calculate open-channel discharge.
• B. Q = (1/n) A R^(2/3) S^(1/2); used to calculate discharge in closed conduits.
• C. Q = (1/n) A R^(2/3) S^(1/2); used to calculate open-channel discharge.
• D. Q = (1/n) A R^(2/3) S^(1/2); used to calculate seepage rates.

Answer: (C)