This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
[{'content': 'Intercalated discs are seen in \nSelect and explain. \nA. Iris, B. Cardiac muscle, C. Musculotendinous endings, D. Nerve bundles', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans: b) Cardiac muscleIntercalated discs are cell membranes that separate individual cardiac muscle cells from one another. Cardiac muscle fibres are made up of many individual cells connected in series and in parallel in such a way that they form permeable "communicating junctions"- gap junctions that allow free diffusion of ions.', 'role': 'assistant'}]