Correct Answer - C
Algae are usually aquatic, either marine or fresh water. Only a few algae occur in moist terrestrial habitats like tree trunks, wet rocks, moist soil, etc. palnt body is thallus (a form without any differentiation into root, stem ad leaves.) sexual, asexual and vegetative modes of reproduction are abundant. form and size of algae range from microscopic unicellular forms like chlamydomonas, to colonial forms like volvox and to filamentous forms like ulothrix and spirogyra.