What is the main difference between a prokaryotic cell and a eukaryotic cell?

The different about these organisms is that eukaryotic cells have a membrane-bound nucleus and prokaryotic cells don't. Only eukaryotic cells have its genetic material surrounded by a membrane. 

i would go with b

cytokinesis occurs after telophase so that eliminates d

and the entire reason for cytokinesis is for cellular reproduction

if you know your abc's you should be able to get your answer or just use google