Pick out the correct statement pertaining to transition/ entrance length in fluid flow.

• A. The length of entrance region of pipe, in which full development of fluid flow takes place such that velocity profile does not change downstream, is called the transition length
• B. Transition length for laminar flow of Newtonion fluids in a pipe of diameter 'd' is equal to 0.05. D.NRe
• C. Transition length for turbulent flow of Newtonion fluids in a smooth pipe of diameter 'd' is equal to 50 D
• D. All of the above