The correct option is D Archaeocytes
Archaeocytes or amoebocytes are indifferent commonly amoeboid interstitial cell found in sponges. They are totipotent and have varied functions depending on the species. Archaeocytes are along with other specialized sponge cells including collencytes and structural elements called as spicules. They move about within the mesohyl with amoeba-like movements. Hence, option D is correct.