Explanation:

• Red Tide is a misnomer for algal blooms. There may or may not be actual discoloration of water. The colour is that of the algae which can be red, brown as well as green. 1st is incorrect
• The name “red tide” comes from the fact that the overgrowth of algae can cause the colour of the water to turn red.
• The red tides caused by the dinoflagellate Gonyaulax (unicellular algae) are serious because this organism produces powerful toxins (saxitoxin and gonyautoxins) that can kill aquatic organisms.Red tides can also lead to die-offs of invertebrates, including shrimp, sponges, sea urchins, crabs and certain shellfish but Not all aquatic animals.
• The phenomenon is in no manner connected with tides. So option C is eliminated.
• Therefore, none of the statements are correct and hence answer D.