ADH takes part in
(a) Water retention in urine
(b) N a + reabsorption
(c) Reducing urea formation
(d) Absorption of water from urine

Options

A. Water retention in urine
B. `Na^(+)` reabsorption
C. Reducing urea formation
D. Absorption of water from urine

Answer

To solve the question regarding the role of ADH (Antidiuretic Hormone), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding ADH**:
- ADH, or Antidiuretic Hormone, is a hormone produced by the hypothalamus and released by the posterior pituitary gland. Its primary function is to regulate water balance in the body.

2. **Function of ADH**:
- ADH acts primarily on the kidneys, specifically on the collecting ducts and the distal convoluted tubule (DCT) of the nephron. Its main role is to promote water reabsorption back into the bloodstream.

3. **Analyzing the Options**:
- **Option (a): Water retention in urine**: This statement is misleading. ADH promotes water reabsorption, which decreases the amount of water excreted in urine, but it does not retain water in urine.
- **Option (b): Na+ reabsorption**: This is primarily the function of another hormone called aldosterone, not ADH.
- **Option (c): Reducing urea formation**: ADH does not play a role in urea formation; this is incorrect.
- **Option (d): Absorption of water from urine**: This is the correct function of ADH, as it facilitates the reabsorption of water from the filtrate in the nephron back into the blood.

4. **Conclusion**:
- Based on the analysis of the options, the correct answer is **(d) Absorption of water from urine**.

### Final Answer:
ADH takes part in (d) Absorption of water from urine.

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