Since the hemolymph of crustaceans leaves the heart by arteries,why is it considered an open rather than a closed system?

A)The hemolymph lacks any respiratory pigments.
B)The hemolymph flows through the hemocoel and returns via venous sinuses rather than enclosed veins.
C)The heart does not pump hemolymph but it moves by ciliary action instead.
D)The arteries "dead end" and the hemolymph must backflow through the arteries.
E)The hemolymph lacks any respiratory function.