Which of the following will lead to an increase in glomerular fluid filtration in the kidneys?

Options

A. An increase in the protein concentration in the plasma.
B. An increase in the fluid pressure in Bowman's space.
C. An increase in the glomerular capillary blood pressure
D. A decrease in the glomerular capillary blood pressure

Explanation

To determine which option will lead to an increase in glomerular fluid filtration in the kidneys, we need to understand the factors that influence glomerular filtration rate (GFR).

### Step-by-Step Solution:

1. **Understanding Glomerular Filtration**:
- Glomerular filtration is the process by which the kidneys filter blood, removing excess wastes and fluids. The rate at which this occurs is known as the glomerular filtration rate (GFR).

2. **Key Factors Affecting GFR**:
- The GFR is primarily influenced by three factors:
- The size of the filtrate.
- The electric charge of the filtrate.
- The glomerular capillary hydrostatic pressure (blood pressure in the glomeruli).

3. **Role of Glomerular Capillary Hydrostatic Pressure**:
- The glomerular capillary hydrostatic pressure is a critical factor. Under normal conditions, this pressure is approximately 60 mm Hg.
- An increase in this pressure will directly lead to an increase in the GFR, meaning more fluid is filtered from the blood into the Bowman's capsule.

4. **Analyzing the Options**:
- **Option 1**: An increase in protein concentration - This would actually decrease GFR due to increased oncotic pressure.
- **Option 2**: An increase in fluid pressure in the Bowman's capsule - This would oppose filtration and decrease GFR.
- **Option 3**: An increase in the glomerular capillary blood pressure - This is the correct option as it directly increases GFR.
- **Option 4**: Not specified, but likely irrelevant based on the context.

5. **Conclusion**:
- The correct answer is that an increase in the glomerular capillary blood pressure will lead to an increase in glomerular fluid filtration.

### Final Answer:
**An increase in the glomerular capillary blood pressure.**