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: Physiology
[{'content': 'Cause of vasodilation in spider nevi \nSelect and explain. \nA. Testosterone, B. Estrogen, C. FSH, D. Hepatotoxin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. EstrogenIn chronic liver disease (especially cirrhosis) and pregnancy, impaired estrogen metabolism and consequent hyper estroenemiaQ leads to spider angiomata/nevi (superficial, toous aerioles, that unlike simple telangiectases, typically fill from the center outwards and occur invariably on upper half of body) and palmar erythema (mottled redness of thenar & hypothenar eminences).', 'role': 'assistant'}]