This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
Most common type of choledochal cyst? 
Select and explain. 
A. Type 1, B. Type 2, C. Type 3, D. Type 6
A: Type 1
Answer: A: Type 1 
Explanation: Choledochal cysts are congenital cystic dilatation of biliary tree.The most common type of choledochal cyst is Type l (Todani modification of Alonso-Lej classification),i.e.,Dilatation of extrahepatic biliary tree(approx.75%).It can be cystic(Type la),focal segmental/saccular(Type lb) or fusiform(Type lc).Choledochal cyst presents with the triad of right upper quadrant pain,jaundice,palpable abdominal mass. Reference:SRB's manual of surgery,5th edition,page no:637.