Veins that return blood directly to the heart include the?

Veins
a. carry blood away from the heartb. carry blood under very high pressurec. may contain valves and are lined with endothelium
d. are described as strong, rigid vessels that always carry oxygenated blood
e. have thick, many layered walls

Veins that return blood directly to the heart include the
a. brachiocephalic veinb. superior vena cavac. portal vein
d. azygos vein
e. pulmonary arteries