Explanation
The principal site for concentration of urine is the Loop of Henle, not the DCT (Distal Convoluted Tubule).
The Loop of Henle, which is part of the nephron in the kidney, plays a crucial role in the formation of concentrated urine by creating a concentration gradient in the surrounding fluid. As the fluid flows through the Loop of Henle, water is reabsorbed and the concentration of solutes, such as urea and sodium, increases. This allows the kidneys to conserve water and maintain the body's fluid balance.
