Which statements are part of the theory of endosymbiosis? Select all that apply.

Some early eukaryotic cells engulfed photosynthetic prokaryotes, which evolved into chloroplasts.
Early prokaryotes were able to carry out aerobic respiration and were engulfed by eukaryotic cells.
Early anaerobic prokaryotes engulfed aerobic prokaryotes, which evolved into mitochondria.
The first cells that appeared on Earth were eukaryotic and were engulfed by prokaryotic cells.