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: Ophthalmology
The technique of blocking the facial nerve at the neck of mandible is: 
Select and explain. 
A. Van Lint's block, B. O'Brien's block, C. Nadbath block, D. Atkinson's block
B: O'Brien's block
Answer: B: O'Brien's block 
Explanation: Ans. O'Brien's block