The correct option is C Algae
The term "Autotrophs" refer to organisms, that can produce their own food from the inorganic substances found in the surroundings. Algae which are predominantly aquatic organisms carry out photosynthesis to prepare their food. These fresh water, brackish and marine water inhabitants with no differentiation of stem, roots and leaves make use of the chlorophyll and other photosynthetic pigments present in their thallus for photosynthesis.