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
Festooned pupil results from: 
Select and explain. 
A. Irregular dilatation of pupil with atropine in the presence of segmental posterior synechiae, B. Annular synechiae, C. Occlusion pupillae, D. All of the above
A: Irregular dilatation of pupil with atropine in the presence of segmental posterior synechiae
Answer: A: Irregular dilatation of pupil with atropine in the presence of segmental posterior synechiae 
Explanation: Ans. Irregular dilatation of pupil with atropine in the presence of segmental posterior synechiae