**Core Concept:** Urea reabsorption is the process by which the kidneys reabsorb filtered urea from the renal tubules back into the bloodstream, contributing to maintaining nitrogen balance and regulating blood urea concentration. Urea is a waste product of protein catabolism and needs to be eliminated from the body.

**Why the Correct Answer is Right:**
The net urea reabsorption rate is the difference between the amount of urea taken up by the renal tubules and the amount excreted in the urine. In a healthy individual, approximately 95% of the filtered urea is reabsorbed. This allows the kidneys to maintain nitrogen balance, preventing the accumulation of urea, which can lead to toxicity.

**Why Each Wrong Option is Incorrect:**
Option A is incorrect because it does not represent the correct net reabsorption rate in percentages.
Option B is incorrect as it is a process, not a numerical value representing the net reabsorption rate.
Option C is also incorrect, as it is unrelated to urea reabsorption and does not represent a percentage.
Option D is incorrect as it does not represent the net reabsorption rate in percentages.

**Clinical Pearl:**
The kidneys play a crucial role in maintaining nitrogen balance and regulating blood urea concentration, which is essential for the proper functioning of various body systems. A decrease in urea reabsorption can lead to uremia and uremic symptoms, while excessive reabsorption can result in hyperuricemia. Understanding the net urea reabsorption rate is essential for clinicians to diagnose and manage kidney disorders affecting urea handling.