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
Condition associated with prolonged muscle contraction followed by slow muscle relaxation includes 
Select and explain. 
A. Myotonia, B. Dystonia, C. Mitochondrial Myopathies, D. Hypotonia
A: Myotonia
Answer: A: Myotonia 
Explanation: (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.