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: Medicine
[{'content': 'Which one of the following is false about autosomal dominant disorders. \nSelect and explain. \nA. Mutated genes can express themselves in heterozygous state, B. Recurrence risk of 25% for parents with a previous affected child, C. Males and females are equally affected, D. Usually defects of structural proteins or receptors', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Recurrence risk is 50%.', 'role': 'assistant'}]