Common bile duct is formed when:
(1) Right and left hepatic ducts are fused
(2) Bile duct is fused with pancreatic duct
(3) Cystic duct is fused with right hepatic duct
(4) Cystic duct (duct of gall bladder) is fused with a common hepatic duct
(4) The duct of gall bladder called as cystic duct along with the hepatic duct from the liver forms the common bile duct.