Prokaryotic Cell — Definition & Examples

Which of the following would be considered a prokaryote?

Image Source A: By NIAID CC BY 2.0, via Wikimedia Commons

Image Source B: By designerpoint CC0, via pixabay.com

Image Source C: By Arria Belli CC BY-SA 3.0, via Wikimedia Commons

Image Source D: By Ranveig CC BY-SA 3.0, via Wikimedia Commons