This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
Which of the following membranes has the highest protein content per gram tissue 
Select and explain. 
A. Myelin sheath, B. Outer mitochondrial Membrane, C. Sarcoplasmic Reticulum, D. Inner Mitochondrial membrane
D: Inner Mitochondrial membrane
Answer: D: Inner Mitochondrial membrane 
Explanation: The membrane with the highest protein content is inner mitochondria The membrane with highest lipid content is myelin sheath Protein to Lipid ratio in Different Membranes Membranes Protein:Lipid Ratio Myelin 0.23 Human RBC 1.1 Mitochondrial outer membrane 1.1 Sarcoplasmic reticulum 2.0 Mitochondrial inner membrane 3.2 Ref: Harper's illustrated Biochemistry 31st edition Pgno: 1124