This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other Papulosquamous Disorders, Subject name: Skin
Hanging curtain sign seen in? 
Select and explain. 
A. Pityriasis rosea, B. Pityriasis Versicolor, C. Pityriasis rubra pilaris, D. Pityriasis lichenoides chronica
A: Pityriasis rosea
Answer: A: Pityriasis rosea 
Explanation: ANSWER: (A) Pityriasis roseaREF: Dermatology. 1995; 190(3): 252. PubMed PMID: 7599393, Clinical Pediatric Dermatology - By Thappa page 104PITYRIASIS ROSEAThe 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 curtain sign)