Euglenas are unicellular organisms. They are both self feeders (autotrophs) and other-feeders (heterotrophs). Which statement summarizes the heterotrophic activities of euglenas?

A. They carry out photosynthesis in sunny places.

B. They are colorless and feed on other smaller cells,

C. They contain chloroplasts with chlorophyll.

D. They live in water and have tail-like structures.