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: Radiology
Bead cystogram is used for the diagnosis of: 
Select and explain. 
A. Ca bladder, B. Stress incontinence, C. Thimble bladder, D. Diveiculum
B: Stress incontinence
Answer: B: Stress incontinence 
Explanation: Stress incontinence