The correct answer is freshwater.Most green algae occur in fresh water, usually attached to submerged rocks and wood or as scum on stagnant water, there are also terrestrial and marine species.Free-floating microscopic species serve as food and oxygen sources for aquatic organisms.Green algaeThe green algae are a large, informal grouping of algae consisting of the Chlorophyta and Charophyta/Streptophyta.Green algae have chloroplasts that contain chlorophyll a and b, giving them a bright green colour, as well as the accessory pigments beta carotene and xanthophylls in stacked thylakoids.The cell walls of green algae usually contain cellulose, and they store carbohydrates in the form of starch.Important PointsAlgae can grow anywhere there is light and water.Using distilled water in one's water fountain will help reduce the number of algae that grows due to the water being pure.