In case of turbulent flow of fluid through a circular pipe, the __________________?

• A. Mean flow velocity is about 0.5 times the maximum velocity
• B. Velocity profile becomes flatter and flatter with increasing Reynolds number
• C. Point of maximum instability exists at a distance of 2r/3 from the pipe wall (r = pipe radius)
• D. Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more