For Calculation of Reynolds number in case of fluid flowing in pipe, solid motion in fluid and in mixing respectively, the density and viscosity of the following is taken into consideration Select one: a. Fluid in case of mixing and pipe flow, solid in case of solid motion in fluid b. Viscosity with respect to fluid in all cases and density with respect to solid in solid motion in liquid c. Viscosity with respect to fluid in all cases and density with respect to solid in solid motion in liquid and density of material of construction of impeller in case of mixing d. Fluid into consideration in all cases