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: Ophthalmology
[{'content': 'Which of the following is the least common corneal dystrophy – \nSelect and explain. \nA. Macular dystrophy, B. Lattice type I, C. Lattice type III, D. Granular corneal dystrophy', 'role': 'user'}, {'content': "Answer: A \nExplanation: Epithelial basement membrane dystrophy is the most common anterior corneal dystrophy.\nLattice dystrophy is the most common stromal corneal dystrophy (Lattice Type I is the commonest\nMacular dystrophy is the least common stromal dystrophy.\nFuch's endothelial dystrophy is the most common Posterior (endothelial) corneal dystrophy.", 'role': 'assistant'}]