EXPLANATION:Kidneys are the excretory organs in the majority of mammals including humansThey play a vital role in the body by performing the following functionsKidneys regulate water and electrolyte balance i.e osmoregulation.Kidneys remove the metabolic waste and foreign chemicals out of the bodyThey regulate the acid-base balance in the body.Kidney perform these functions by the NephronsA NEPHRON is a functional and structural unit of the kidney (organ), which is involved in the process of excretion.It is made up of renal corpuscle or Bowman’s CAPSULE, Glomerulus, PROXIMAL Convoluted tubule, Loop of Henle, and DISTAL Convoluted Tubule.Bowman’s capsule is a double-walled cup-like structure in which the dense network of blood capillaries (Glomerulus) is present.Thus, the correct option is ''all of these functions''