The kidneys play several crucial physiological roles in maintaining homeostasis.

Among the options provided:
- Option 1: Erythropoietin secretion - The kidneys produce and secrete erythropoietin, a hormone that stimulates red blood cell production in the bone marrow, especially in response to hypoxia. This is an important endocrine function of the kidneys.

- Option 2: Acid-base balance regulation - The kidneys regulate the body's pH by excreting hydrogen ions and reabsorbing bicarbonate, helping maintain acid-base homeostasis.

- Option 3: Glycogen storage - This is not a function of the kidneys. Glycogen storage primarily occurs in the liver and skeletal muscles. The kidneys do not store glycogen.

- Option 4: Glomerular filtration - This is a fundamental function of the kidneys, where blood plasma is filtered through the glomeruli to form urine. It is essential for removing waste products and excess substances from the bloodstream.

In summary, the kidneys do not store glycogen; this role is reserved for the liver and muscles. The other options represent key physiological roles of the kidney.

Reference: Guyton and Hall Textbook of Medical Physiology, 14th Edition, Chapter 26: The Urinary System and Regulation of Extracellular Fluid Volume and Osmolarity, Page 335-350