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': 'Blood born metastasis is unusual of - \nSelect and explain. \nA. Osteosarcoma, B. Medullary carcinoma breast, C. Chorio carcinoma, D. Renal cell carcinoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Lymphatic or vascular invasion is never seen in medullary Carcinoma of breast.\nOsteosarcoma, Choriocarcinoma and RCC metastatize to distant organs by vascular invasion.', 'role': 'assistant'}]