If viscosity of fluid is more, the thickness of boundary layer is

Explanation

The correct answer is that the thickness of the boundary layer is More when the viscosity of the fluid is higher. Viscosity is a measure of a fluid's resistance to flow. A higher viscosity means the fluid flows more slowly and with more resistance, leading to a thicker boundary layer. The boundary layer is the region of fluid in the immediate vicinity of a bounding surface where the effects of viscosity are significant. Options B and C are incorrect because they do not account for the direct relationship between viscosity and boundary layer thickness. Option D is incorrect because the relationship is predictable and well-documented in fluid dynamics literature.