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
Peripheral anterior synechiaeafteran attackof acute congestive glaucoma occur earliest in the: 
Select and explain. 
A. Lower pa, B. Upper pa, C. Lower and inner pa, D. Lower and outer pa
B: Upper pa
Answer: B: Upper pa 
Explanation: Ans. Upper pa