D because the common types of phytoplankton is cyanobacteria,
silica-encased diatoms, dinoflagellates, green algae, and chalk-coated coccolithophores. 
 
        
             
        
        
        
Answer:
D. Nucleoid
Explanation:
As prokaryotic cells do not have any organelles, they use a nucleoid to store their prokaryotic DNA.