Metanephridia Differ from Protonephridia in All of the Following Ways

Metanephridia differ from protonephridia in all of the following ways EXCEPT that:

A) the urine produced in both systems is more dilute than the body fluids.
B) metanephridia are surrounded by an extensive capillary network, whereas protonephridia are not.
C) selective reabsorption of materials occurs via cells lining the tubules in protonephridia and via capillaries in metanephridia.
D) fluid enters metanephridia through a funnel-shaped opening.
E) fluid from the body cavity enters protonephridia without first being filtered.