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
Cause of vasodilation in spider nevi 
Select and explain. 
A. Testosterone, B. Estrogen, C. FSH, D. Hepatotoxin
B: Estrogen
Answer: B: Estrogen 
Explanation: 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).