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: Anatomy
TRUE about ureter's entry into the bladder: 1. At medial angle of trigone 2. At lateral angle of trigone 3. Make an angle 4. Is straight 5. Valveless 
Select and explain. 
A. 1,3 & 5, B. 2,3 & 5, C. 1,2 & 4, D. 1,3 & 5
B: 2,3 & 5
Answer: B: 2,3 & 5 
Explanation: The ureters enters the bladder wall obliquely to open into it at an angle of its trigone. Ureter Entry To Bladder Ureteric orifices are placed at the posterolateral trigonal angle. The ureter pierces the bladder wall obliquely, and this provides valve like action ( but not true valve), which prevents reverse flow of urine towards kidneys as bladder fills.