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: Anaesthesia
In general, the last muscle to be rendered akinetic with a retrobulbar anesthetic block is – 
Select and explain. 
A. Superior rectus, B. Superior oblique, C. Inferior oblique, D. Levator palpebral superioris
B: Superior oblique
Answer: B: Superior oblique 
Explanation: A properly placed retrobulbar injection is effective within seconds and blocks all extraocular muscles except the superior oblique muscle, affects the ciliary ganglion and anesthetizes the entire globe.