Pressure drop for laminar fluid flow through a circular pipe is given by__________________?

Pressure drop for laminar fluid flow through a circular pipe is given by__________________?

A. 4f (L/D) (v2/2gc) ρ
B. 32 (μLV/gc D2)
C. 16/NRe
D. (fLρ/D) (v2/2gc)