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: Skin
[{'content': 'FTU is a measure of: \nSelect and explain. \nA. Area involved in severe drug reactions, B. Amount of topical drug to be applied, C. Mucosal involvement in pemphigus, D. Concentration of drug in topical preparations', 'role': 'user'}, {'content': 'Answer: B \nExplanation: An approximate practical measure of topical medication is the fingeip unit, the quantity of ointment, extruded from a tube with a nozzle of 5 mm diameter extending from the distal crease of the forefinger to ventral aspect of the fingeip. This unit weighs approximately 0.49 g in males and 0.43 g in females and covers, on average, an area of approx 300 cm2.', 'role': 'assistant'}]