The coefficient of viscosity `(eta)` of a fluid moving steadily between two surface is given by the formula `(f) = etaA dV//dx` where f is the frictional force on the flluid, A is the area in the fluid, and `dN//dx` is velocity gradient inside the fluid at that area. The SI unit of viscosity is given as :
A. `kg m^(-1) s^(-1)`
B. `Nm^(-2) s`
C. Nil
D. Newtons
