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
True statement about smooth muscles 
Select and explain. 
A. 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
A: Presence of Caveolae
Answer: A: Presence of Caveolae 
Explanation: Smooth muscle

No T tubules. Instead it has Caveolae which is invagination of smooth muscle membrane, it has voltage gates L-type Ca2+ channel
No troponin Ca2+ binds Calmodulin
No Z lines. Achorage for actin filaments is provided by dense bodies.