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
Which does not cause relaxation of urinary bladder ? 
Select and explain. 
A. Sympathetic Stimulation, B. Muscarinic receptors, C. Beta receptors, D. None of the above
B: Muscarinic receptors
Answer: B: Muscarinic receptors 
Explanation: Ans. is'b'i.e., Muscarinic receptorsSympathetic stimulation causes relaxation of bladder (detrusor muscle) beta-2 adrenoreceptors.Parasympathetic stimulation cause contraction of bladder (detrusor muscle) muscarinic M3 receptors.