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: Skin
[{'content': 'Patch testing is done for : \nSelect and explain. \nA. Atopic dermatitis, B. Irritant contact dermatitis, C. Allergic contact dermatitis, D. Discoid eczema', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C. Allergic contact dermatitis', 'role': 'assistant'}]