<prompt> True regarding umblilical cord is2018A Two aery and two veinsB One aery and two veinsC Observations of a single umblilical vein is associated with additional anomaliesD Observations of a single umblical aery is associated with additional anomalies  <response>: Umbilical cord contains right and left umbilical aeries, the left umbilical vein, LEFT IS LEFT, remnants of the vitello-intestinal duct and yolk sac. The ground substance of the umbilical cord is made up of Whaons jelly derived from mesoderm. Ref:- Inderbirsingh, pg num:-46 