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: Pharmacology
[{'content': 'Dr. Nitin decided to give oral iron therapy to a patient of iron deficiency anemia. Which of the following adverse effects leads to poor compliance of medicine by the patient? \nSelect and explain. \nA. Epigastric pain and bowel upset, B. Black stools, C. Staining of teeth, D. Metallic taste', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]