Assertion (A): In non-Newtonian fluids, the shear stress at any point is not a linear function of normal distance from the surface.
Reason (R): This behaviour usually arises because the fluid molecules are very large, like polymers or proteins
(A) Both A and R are individually true and R is the correct explanation of A
(B) Both A and R are individually true but R is not the correct explanation of A
(C) A is true but R is false
(D) A is false but R is true