This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lung Tumor, Subject name: Pathology
[{'content': 'A 65-year-old male diagnosed by biopsy a case of squamous cell carcinoma of lung, has very high serum calcium levels. Probable cause is? \nSelect and explain. \nA. Parathyroid hormone, B. Parathyroid hormone-related peptide, C. Calcitonin, D. Calcitonin-related peptide', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Paraneoplastic syndromes The most impoant mechanism is the synthesis of a parathyroid hormone-related protein (PTHrP) by tumor cells (Commonly in Squamous cell carcinoma) leading to Hypercalcaemia.', 'role': 'assistant'}]