This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pharmacology
[{'content': 'In spider nevi, dilatation of blood vessels is due to: \nSelect and explain. \nA. Testosterone, B. Estrogen, C. Hepatotoxins, D. FSH', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (B) Estrogen(Ref: Wikipedia)A spider angioma (also known as a nevus araneus, spider nevus, vascular spider, and spider telangiectasia) is a type of telangiectasis found slightly beneath the skin surface. The central red dot is the dilated arteriole and the red "spider legs" are small veins carrying away the freely-flowing blood. The dilation is caused by increased estrogen levels in the blood.', 'role': 'assistant'}]