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 for smooth muscle contraction is all excepta) More Latching when lower cross-bridge formation.b) Dephosphorylation causes definite relaxationc) LC phosphatase is essential for binding d) Slow & prolonged contractile response independent of nerve supplye) Length tension relationship does not exist 
Select and explain. 
A. a, B. c, C. ac, D. bc
D: bc
Answer: D: bc 
Explanation: Dephosphorylation in smooth muscle does not guarantee relaxation, as some myosin will remain latched to actin.
Light chain phosphatase helps in dephosphorylation, not binding.