Selective process are

Options

A. Fitration and secretion
B. Secretion and reabsorption
C. Reabsorption and filtration
D. Filtration, secretion and reabsorption

Answer

### Step-by-Step Solution

1. **Understanding Selective Process**:
- The selective process refers to the mechanisms in the kidneys that allow for the reabsorption and secretion of specific solutes and ions. This ensures that essential substances are retained in the body while waste products are excreted.

2. **Components of Selective Process**:
- The selective process primarily includes two key components: **secretion** and **reabsorption**.
- **Secretion** is the transfer of substances from the blood (capillaries) into the renal tubule, which is part of the kidney. This process allows the body to eliminate waste products and excess ions.
- **Reabsorption** is the process where water and necessary solutes are removed from the tubular fluid (the fluid within the renal tubule) and returned to the bloodstream. This ensures that vital substances are not lost in urine.

3. **Filtration vs. Selective Process**:
- It is important to note that **filtration** is not considered a part of the selective process. Filtration is a passive process where blood plasma is filtered in the renal tubule, allowing both waste materials and essential substances to pass through without selection.

4. **Conclusion**:
- Therefore, the selective processes in the kidneys are **secretion** and **reabsorption**. These processes are crucial for maintaining homeostasis by regulating the composition of body fluids.

### Final Answer
The selective processes are **secretion** and **reabsorption**.

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