Final answer:
The prokaryotic cells that built stromatolites are classified as bacterial and archaean prokaryotic cells.
Step-by-step explanation:
The prokaryotic cells that built stromatolites are classified as d. bacterial and archaean prokaryotic cells. Prokaryotes are predominantly single-celled organisms of the domains Bacteria and Archaea. Stromatolites are layered rock-like structures formed by the activities of prokaryotes, specifically bacteria and archaea, that live in shallow water environments.