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: Physiology
Marker enzyme of mitochondria are/is - 
Select and explain. 
A. Na+ – K+ ATPase, B. Glutamate dehydrogenase, C. Lactate dehydrogenase, D. No specific enzyme
B: Glutamate dehydrogenase
Answer: B: Glutamate dehydrogenase 
Explanation: Markers of Plasma membrane - 5 '-Nucleotidase, Adenylyl cyclase, Na+ K+ ATPase
Marker of Endoplasmic reticulum- Glucose-6-phosphatase
Markers of Golgi apparatus- GlcNAc transferase 

Golgi mannosidase 
Galactosyltransferase, Sialyltransferase

Marker of Mitochondria- ATP synthase, Glutamate dehydrogenase
Marker of Peroxisome- Catalase
Marker of Cytosol- LDH