This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Medicine
[{'content': 'Condition associated with prolonged muscle contraction followed by slow muscle relaxation includes \nSelect and explain. \nA. Myotonia, B. Dystonia, C. Mitochondrial Myopathies, D. Hypotonia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (A) Myotonia # Myotonia is a symptom of a small handful of certain neuromuscular disorders characterized by delayed relaxation (prolonged contraction) of the skeletal muscles after voluntary contraction or electrical stimulation.> Myotonia may present in the following diseases with different causes related to the ion channels in the skeletal muscle fiber membrane (Sarcolemma).> Myotonia is present in Myotonia congenita, Paramyotonia Congenita and myotonic dystrophy.', 'role': 'assistant'}]