This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cytotoxic Anticancer Drugs, Subject name: Pharmacology
[{'content': 'A 45 year old female was diagnosed with breast carcinoma. She was operated and is taking tamoxifen therapy for the last 1 year. Now she is complaining of bleeding per vaginum. If this is due to the adverse effect of tamoxifen, the most likely cause is:- \nSelect and explain. \nA. Development of bleeding disorder, B. Development of endometrial carcinoma, C. Development of ovarian carcinoma, D. Development of cervical cancer', 'role': 'user'}, {'content': 'Answer: B \nExplanation: - Tamoxifen and Toremifene are selective estrogen receptor modulators (SERMs) that are useful for chemoprevention as well as treatment of both early stage and metastatic breast carcinoma. - These increase the risk of endometrial carcinoma.', 'role': 'assistant'}]