This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
In prokaryotes, which of the following is present: 
Select and explain. 
A. Nucleolus, B. ER, C. Golgi bodies, D. Muramic acid
D: Muramic acid
Answer: D: Muramic acid 
Explanation: Muramic Acid is one of the important components of the peptidoglycan wall present in the cell wall of prokaryotic cells