Which of the following is true about aldosterone? A. Its main site of action is the P-cell of the proximal tubule of the nephron. B. None of the above statements are true. C. The release of aldosterone is stimulated by low plasma [K+]. D. Aldosterone is a hormone that is released by the zona glomerulosa of the adrenal medulla. E. It is generally released in response to low blood pressure or very high plasma osmolarity.