Answer:
The correct answer is green algae.
Step-by-step explanation:
Euglena is unicellular flagellate protists found in the freshwater rich in organic material.
They show both modes of nutrition that is heterotrophic and phototropic. Their phototropic mode is due to the presence of chloroplasts with three membranes which produce energy through photosynthesis.
The chloroplasts of Euglena resembles the chloroplast of green algae and thought to have evolved from green algae and not directly from blue-green algae or cyanobacteria as the third membrane of Euglena is originated from the plasmalemma of the symbionts.
Thus, green algae are the correct answer.