Concept:Parasitic flatworms absorb digested nutrients directly through their body surface.Explanation:These flatworms live inside the host's intestine, where food is already digested.They absorb this digested food directly through their body surface.Since digested food is absorbed in a ready form, a complete alimentary canal is not required.Thus, the absence of an alimentary canal is linked to the absorption of digested food by the body.Answer:C. its body absorbs digested food