Which of the following phyla includes organisms that cause the “red tide” phenomenon?

Red tides are dense blooms of dinoflagellates such as Karenia and Gonyaulax, whose pigments colour the water red and some of which release toxins. Kinetoplastida are flagellated protozoans such as Trypanosoma and Leishmania, while Arthropoda and Porifera are animal phyla that do not cause blooms.