If the relationship between the shear stress $\tau$ and the rate of shear strain $(\frac{du}{dy})$ is expressed as $\tau =\mu (\frac{du}{dy})^{n}$ then the fluid with exponent n > 1 is known as which one of the following?
a. Bingham plastic
b. Dilatant fluid
c. Newtonian fluid
d. Pseudo plastic fluid