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': 'Activation energy is free energy difference between the ____: \nSelect and explain. \nA. Substrate & product, B. Substrate & transition state, C. Transition & product, D. Sum of all the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Activation energy is free energy difference between the substrate & transition state.\nActivation energy may be also be defined as the minimum energy required to start a chemical reaction.\nReference-Harper 30th edition pg -75', 'role': 'assistant'}]