Question

what is secondary endosymbiosis? a eukaryotic cell engulfing another eukaryotic cell a eukaryotic cell engulfing a prokaryotic cell a eukaryotic cell engulfing two prokaryotic cells

Explanation:

Secondary endosymbiosis is the process where a eukaryotic cell engulfs another eukaryotic cell (which itself may have originated from a previous endosymbiotic event). The first option describes this, while the second is primary endosymbiosis (eukaryotic engulfing prokaryotic) and the third is not the definition of secondary endosymbiosis.

Answer:

A. a eukaryotic cell engulfing another eukaryotic cell