This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autoimmune skin disorders, Subject name: Dental
Female presents with history of color change from pallor to cyanosis on exposure to cold in fingers.This condition is mostly associated with ? 
Select and explain. 
A. Scleroderma, B. Leukemia, C. Lung infections, D. Hepatosplenomegal
A: Scleroderma
Answer: A: Scleroderma 
Explanation: Raynauds phenomenon- characterised by sequential colour changes of pallor,cyanosis, and redness accompanied by tingling numbness or pain.It is due to exaggerated vascular response to cold. manifestations of systemic sclerosis - sclerodactyly,telengiectasia, Raynaud's phenomenon, oesophageal disease, lung involvement, cardiac manifestations and renal involvement. Reference IADVL's concise textbook of dermatolology page 1230