Question Detail
Question
All these animals have digestive tracts except ______.
Correct Answer
Option D is the correct answer.
Detailed Explanation
Sponges (Phylum Porifera) are simple multicellular animals that lack true tissues and organs, including a digestive tract. They filter feed intracellularly. Cnidarians and Platyhelminthes have incomplete digestive tracts (a single opening), while starfishes have a complete digestive tract.
Hint
Which of these animal groups is known for its very simple body plan, lacking true organs?