It's kinda hard to read can you put another pic or something?
Unicellular organisms excrete waste by a contractile vacuole. A vacuole is membrane-enveloped organelle in a cell that is found in lots of microorganism. It expands, filling with water then contracts, removing all of its contents to the exterior of the cell.
Answer:
I would say chordates. (Not absolutely sure so double check)
Explanation:
Chordates have a dorsal nerve cord, which is super close to a spinal cord. (Which vertebrates have.)