Concept:The foetus receives oxygen and nutrients from the mother through the connection between the placenta and the umbilical cord.Explanation:In the diagram, labels III and IV represent the umbilical cord and the placenta.The placenta attaches to the dam (mother) and allows exchange of dissolved oxygen and nutrients.The umbilical cord connects the foetus to the placenta and carries these substances to the foetus.Therefore, both parts III and IV are needed for the foetus to obtain dissolved oxygen and nutrients from the dam.Answer:D. III and IV
