Abiogenesis of primitive polypeptides, the pro-proteins, in primitive sea was followed by formation of large spherical colloidal aggregates of proteins that remain suspended as droplets in sea water. It was driven by dehydration/opposite charge attraction. The hydrophilic amino acids attracted water molecules and led to formation of a water envelop around each aggregate. Aggregation of fat/lipid molecules formed a coating membrane around each aggregate to hold the colloidal particles together thereby facilitating chemical reactions among them. A protobiont/eobiont/protocell is defined as aggregate of abiotically produced organic molecules surrounded by non-unit membrane. Thus, the above mentioned colloidal aggregate is protobiont/eobiont/protocell. It is called so because of its role as progenitor of first life form, the prokaryotic bacteria like cell. Thus, the correct answer is option D.