Assertion (A): In humans, major amount of water is absorbed by the tubular part of nephron.
Reason (R): Absorption of water depends on the dissolved waste to be excreted from the body.

Options

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is NOT the correct explanation of A.
C. A is true but R is false.
D. A is false and R is true.

Explanation

To solve the question regarding the assertion and reason, we will analyze both statements step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that in humans, the major amount of water is absorbed by the tubular part of the nephron.
- This is true because the nephron, which is the functional unit of the kidney, is responsible for filtering blood and reabsorbing water. The proximal convoluted tubule (PCT) is where a significant amount of water reabsorption occurs.

2. **Understanding the Reason (R)**:
- The reason states that the absorption of water depends on the dissolved waste to be excreted from the body.
- This statement is also true. The concentration of dissolved waste products in the urine can influence the amount of water reabsorbed. For instance, if there are more waste products, the body may retain more water to dilute these wastes.

3. **Analyzing the Relationship**:
- While both statements are true, the reason does not correctly explain the assertion. The assertion is about where water absorption occurs (the nephron), while the reason discusses factors influencing water absorption (dissolved waste concentration).
- Therefore, the assertion and reason are both true, but the reason is not the correct explanation for the assertion.

4. **Conclusion**:
- Based on the analysis, the correct option is: "Both assertion and reason are true, and the reason is not the correct explanation of the assertion."

### Final Answer:
The correct answer is option 2: Both assertion and reason are true, and reason is not the correct explanation of assertion.

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