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': 'Hanging cuain sign seen in? \nSelect and explain. \nA. Pityriasis rosea, B. Pityriasis Versicolor, C. Pityriasis rubra pilaris, D. Pityriasis lichenoides chronica', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Pityriasis rosea REF: Dermatology. 1995; 190(3): 252. PubMed PMID: 7599393, Clinical Pediatric Dermatology - By Thappa page 104 PITYRIASIS ROSEA The primary eruption, herald patch (Mother spot) is a single oval or round patch with a central wrinkled salmon colored area and a darker peripheral zone separated by a "collarette of scales" (when stretched across the long axis, the scales tends to fold across the line of stretch, the so called Hanging cuain sign).', 'role': 'assistant'}]