This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory Chain, Subject name: Biochemistry
Which complex in mitochondrial ETC does not pump out H ions - 
Select and explain. 
A. Complex I, B. Complex II, C. Complex III, D. Complex IV
B: Complex II
Answer: B: Complex II 
Explanation: Ans. is 'b' i.e., Complex II