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
All are inhibitors of oxidative phosphorylation except? 
Select and explain. 
A. Carboxin, B. Oligomycin, C. Valinomycin, D. Atractyloside
A: Carboxin
Answer: A: Carboxin 
Explanation: Carboxin inhibits the transfer of ions from FADH2. Oligomycin, Valinomycin and Atractyloside are inhibitors of oxidative phosphorylation. Oligomycin inhibits flow of protons through Fo. Valinomycin is an ionophore which inhibits oxidative phosphorylation. Atractyloside inhibits translocase.