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
Which of the following is a feature of gram-positive bacteria rather than gram-negative bacteria? 
Select and explain. 
A. Lipid A-containing lipopolysaccharide, B. Lipoprotein in periplasmic space, C. Outer membrane, D. Thick peptidoglycan cell wall
D: Thick peptidoglycan cell wall
Answer: D: Thick peptidoglycan cell wall 
Explanation: Most of the features listed are those of gram-negative bacteria, which have a complex cell envelope consisting of a cytoplasmic (inner) membrane, a periplasmic space containing peptidoglycan and lipoprotein, an outer membrane, and sometimes a capsule. The outer membrane contains lipopolysaccharide which is a major component of endotoxin. The peptidoglycan cell wall of the gram-negative bacteria is thin, while that of the gram-positive bacteria is thick. Other features of gram- positive bacteria include a fairly simple surface with cytoplasmic membrane, peptidoglycan, cell wall, and sometimes, an outer capsule. The cell wall contains lipoteichoic acids.