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 called glomerulus. Filtration occurs as blood pressure forces fluid from the blood in the glomerulus into the lumen of Bowman's capsule (C) Filtration of small molecules passes through three regions of the nephron: the proximal tubule, the loop of Henle, and the distal tubule, which are all permeable to salt but not to water (D) The controlled movement of ions (such as) in the proximal and distal tubules keep the constant pH in the body fluid