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: Anaesthesia
[{'content': 'Anesthetic agent with vasoconstriction is contraindicated in? \nSelect and explain. \nA. Finger block, B. Spinal block, C. Epidural block, D. Regional anesthesia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Vasoconstrictor should not be added for ring block of hands, feet, fingers, toes, penis, pinna as all these organs are supplied by endarteries and ischemic damage may occur.', 'role': 'assistant'}]