Answer: option E.
Filtration.
Explanation:
Digestive system consist of the gastrointestinal tracts, organs that help to breakdown large complex consumed food into to small pieces which can easily be absorbed by the body.
Filtration is not a function of digestive system because it play a major role in circulatory system which help in movement of solutes out of the capillary into interstitial fluid by separating the bigger particles from the smaller particles, filtering out nitrogenous waste and regulating salt concentration .