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
[{'content': 'Repetitive stimulation increases pain sensation, the probable cause is \nSelect and explain. \nA. Hyper-sensitization, B. Decreased reflex time, C. Increase in threshold of pain, D. Decreased receptor area', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Repetitive stimulation causes release of chemical mediators such as histamine, bradykinin, prostaglandins etc, which increase the sensitivity of nociceptors.', 'role': 'assistant'}]