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': 'An elderly male presents with headache, recurrent infections and multiple punched out lytic lesions of x-ray skull. The investigation that will best help in establishing a diagnosis is: \nSelect and explain. \nA. Protein Electrophoresis, B. Serum calcium, C. Alkaline phosphatase levels, D. Acid phosphatase levels', 'role': 'user'}, {'content': "Answer: A \nExplanation: Answer is A (Protein Electrophoresis) Presence of symptoms of hyperviscocity syndrome (Headache), recurrent infections (ineffective defense against infections) and multiple punched out lytic lesions in the skull suggest a diagnosis of Multiple myeloma Protein electrophoresis will help demonstrate a characteristic 'M spike' and help in establishing the diagnosis of inultipk myeloma. Serum Calcium is likely to be elevated while serum alkaline phosphatase levels are likely to be normal. Although both serum calcium and serum alkaline phosphatase levels may be done to suppo a diagnosis of Multiple Mveloma, demonstration of the charachteristic 'M spike' on protein electrophoresis is the single preferred investigation. Classic Triad of Multiple Myeloma Relevant investigations Marrow plasmacytosis > 10% (Bone Marrow examination: Not provided in options) Lytic bone lesions (X-Ray skull: Already performed in patient) Serum/urine M component (Protein Electrophoresis: Suggested next investigation)", 'role': 'assistant'}]