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: Physiology
[{'content': 'True statement about smooth muscles \nSelect and explain. \nA. Presence of Caveolae, B. Ca2+ binds to troponin C, C. The anchorage for actin filaments is given by Z-lines, D. Voltage gates L-type Ca2+ channel are present in T-tubules', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Smooth muscle\n\nNo T tubules. Instead it has Caveolae which is invagination of smooth muscle membrane, it has voltage gates L-type Ca2+\xa0channel\nNo troponin Ca2+\xa0binds Calmodulin\nNo Z lines. Achorage for actin filaments is provided by dense bodies.', 'role': 'assistant'}]