Final answer:
Sewage sludge is an example of an ideal plastic substance because it displays no deformation up to yield stress and flows like a Newtonian fluid beyond it. Rubber latex, blood, and sugar solution do not show this behavior.
Step-by-step explanation:
Materials that exhibit ideal plastic behavior do not deform under stress until a critical value known as the yield stress is reached, beyond which they behave like a Newtonian fluid. Considering the options provided, sewage sludge is an example of an ideal plastic substance. This is because it will not deform when a stress is applied, up to a certain yield stress point. Beyond this point, it will flow like a Newtonian fluid. In contrast, rubber latex, blood, and sugar solution do not display ideal plastic behavior. Rubber latex becomes increasingly difficult to stretch and does not flow like a fluid beyond its yield stress. Blood, which is a non-Newtonian fluid, exhibits different viscosity characteristics depending on the flow conditions. Sugar solution behaves as a typical Newtonian fluid, which means its viscosity remains constant regardless of the shear rate applied.