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: Anatomy
[{'content': 'Cardiac muscle is able to function as a syncy-tium because of the structural presence of \nSelect and explain. \nA. Branching fibres, B. Intercalated disc, C. Protoplasmic bridges between cells, D. Gap-junctions', 'role': 'user'}, {'content': "Answer: D \nExplanation: D i.e. Gap junction Cardiac muscle have characteristic intercalated discQ (always at z line) &skeletal muscle have cross striation; and smooth muscles don't have both.Skeletal muscle has dark & light bands and peripherally placed nucleusQ;where as cardiac muscle has intercalated disc & centrally placed nucleusQEach cardiac muscle has a single nucleusQ. Cardiac muscle fiber branch & interdigitateQ. Cardiac muscle function as a synctium because of presence of gap junctionQ.", 'role': 'assistant'}]