In your biology lab,you use a stereoscopic microscope to observe a living animal that uses only one opening to both take in its food,and also eject its waste products after having eaten and digested the food for metabolism.This body arrangement of the animal is which of the following?
A) incomplete digestive tract B) gastrovascular cavity C) complete digestive tract D) complete digestive tract and a gastrovascular cavity E) incomplete digestive tract and a gastrovascular cavity