The correct option is
A Unicellular
Prokaryotes are the primitive organisms whose cells show simple level of organization. The cytoplasm of a prokaryotic cell is not divided into compartments, that means, the membrane-bound organelles are not present in them. So, nucleus, mitochondria, chloroplasts endoplasmic reticulum etc. are not found. Their genetic material is not surrounded by the membrane and is present in the form of nucleoid. The prokaryotes are unicellular organisms. They do not show multicellularity due to simple cell structure. For example, Bacteria, Blue-Green Algae.
Hence, the correct answer is 'Unicellular'