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: Biochemistry
[{'content': 'Most powerful oxygen free radical is: \nSelect and explain. \nA. Hydroxyradical, B. Hydrogen peroxide, C. Superoxide radical, D. Both 1 & 2', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Most powerful oxygen free radical is Hydroxyradical:\n\nLeast powerful Reactive Oxygen species is Hydrogen peroxide.\nPrecursor of all reactive Oxygen species is Superoxide radical.\nH2O2 is not a free radical but a ROS.\n\nReference- Review of biochemistry by Rebecca James Perumcheril Pg-411', 'role': 'assistant'}]