5. Which of the following statements about excretory system is NOT TRUE?
(A) Nephron is the functional unit of kidney
(B) The nephron consists of a single long tubule and a ball of capillaries calledglomerulus. Filtration occurs as blood pressure forces fluid from the blood in theglomerulus into the lumen of Bowman's capsule
(C) Filtration of small molecules passes through three regions of the nephron: theproximal tubule, the loop of Henle, and the distal tubule, which are all permeable tosalt but not to water
(D) The controlled movement of ions (such as

) in the proximal anddistal tubules keep the constant pH in the body fluid