Which of the following ducts connect the pulmonary trunk to the aorta in the fetus?

A) oval opening
B) venous duct
C) arterial duct
D) umbilical artery
E) umbilical vein

The arterial duct, also known as the ductus arteriosus, connects the pulmonary trunk to the aorta in the fetus. This allows blood to bypass the underdeveloped lungs and instead flows to the rest of the body. The oval opening connects the two atria, the venous duct is not a real structure, the umbilical artery carries deoxygenated blood from the fetus to the placenta, and the umbilical vein carries oxygenated blood from the placenta to the fetus.