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: Medicine
[{'content': 'Estimation of the following hormones is useful while investigating a case of gynaecomastia except \nSelect and explain. \nA. Testosterone, B. Prolactin, C. Estradiol, D. Lutenizing hormone', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]