Option (D) is correct. The provided text states that Mesenchymal stem cells (MSCs) can be isolated from a variety of tissues, specifically listing bone marrow, adipose tissue, and umbilical cord. Additionally, the text mentions that fetal blood and cord blood are rich sources of haemopoietic stem cells. Since options (A), (B), and (C) are all identified as sources for obtaining stem cells in the context, the correct choice is 'All of these'.