Which of the following is the source of hepatic stem cells

ref , Robbins 8/e p83;7/e p91;9/e p28 Hepatic oval cells (HOC) are a small subpopulation of cells found in the liver when hepatocyte proliferation is inhibited and followed by some type of hepatic injury. ... These cells are believed to be bipotential, i.e., able to differentiate into hepatocytes or bile ductular cells It is source of hepatic stem cells