Answer:
Nucleus, mitochondrion, and chloroplast
Step-by-step explanation:
If I were to be a prokaryotic cell that suddenly develops the ability to take on 3 organelles that I do not already have, I would pick a nucleus, a mitochondrion, and a chloroplast.
The presence of the nucleus would enable the freely lying genetic materials in the cytoplasm to become organized and packaged within the nucleus, thereby enabling more controls over transcription and translation processes.
Also, the presence of mitochondrion would increase the efficiency of energy generation through oxidative phosphorylation and the chloroplast will enable the cell to be able to manufacture its own food through photosynthesis rather than depending on external sources for foods.