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: Surgery
Which muscle is being injected by botulin? 
Select and explain. 
A. Masseter, B. Buccinator, C. Lateral Pterygoid, D. Temporalis
C: Lateral Pterygoid
Answer: C: Lateral Pterygoid 
Explanation: The technique for injecting botulinum toxin into the inferior lateral pterygoid muscle. Note that there is an electrode on the chin and a wire attached to the needle so that the electromyographic activity can be monitored at the needle tip. B, Once the needle is placed to the proper depth, the patient is asked to push against resistance provided by the operator. If the needle is properly placed in the inferior lateral pterygoid muscle, the electromyogram will increase on the monitor. Once the proper position has been verified, the botulinum toxin is injected.