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: Pathology
[{'content': 'The most definite feature of a malignant tumour is: \nSelect and explain. \nA. Haemorrhage, B. Increased mitoses, C. Metastasis, D. Necrosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]