The analogy is as follows blood cell: Eukaryotic cell,  bacteria: prokaryotic cell
Answer: Option A
Step-by-step explanation:
 The eukaryotic cells are cells that have a well-defined membrane bound organelles and well defined ''nucleus'', a prokaryotic cell does not have any of these characteristics. 
Moreover a prokaryotic cell mostly is present in microorganisms whereas a eukaryotic cell is mostly present in macro and multicellular organisms. But there are exceptions to it which contain a single celled ''eukaryote''. Blood cell is a eukaryotic cell whereas a bacteria is a single celled ''prokaryote''.