What is the characteristic variation shown by the thixotropic fluids in their shear stress vs. rate of shear strain graph?

• A. shear stress increases with increase in rate of shear strain
• B. shear stress decreases with increase in rate of shear strain
• C. shear stress shows variation only after a definite shear stress is reached
• D. shear stress has decreasing constant and then variation relationship with rate of shear strain