In Planarian Flatworms,which Organ(s)rids the Body of Excess Water and Soluble

Question

In planarian flatworms,which organ(s)rids the body of excess water and soluble wastes?  
A) Coelom
B) Malpighian tubule
C) Nephridia
D) Protonephridia
E) Kidney

Accepted Answer

In planarian flatworms, Protonephridia is responsible for ridding the body of excess water and soluble wastes.