This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
Which of the following effects of adrenaline would be block the by phentolamine but not by propanonol 
Select and explain. 
A. Cardiac stimulation, B. Relaxation of bronchial smooth muscle, C. Relaxation of uterus, D. Contraction of radiap smooth muscle in the iris
D: Contraction of radiap smooth muscle in the iris
Answer: D: Contraction of radiap smooth muscle in the iris 
Explanation: Ref-KDT 6/e p123 Smooth muscle of iris contain alpha receptor whereas hea,bronchus and uterus possess ba-adrenergic receptor