The element which plays an important role in opening and closing of stomata is

Options

A. Cl
B. K
C. P
D. Ca

Answer

To solve the question regarding the element that plays an important role in the opening and closing of stomata, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Question**: The question asks which element is crucial for the opening and closing of stomata in plants.

2. **Review the Options**: The options provided are:
- a. Chlorine
- b. Potassium
- c. Phosphorus
- d. Calcium

3. **Analyze Each Option**:
- **Chlorine**: While chlorine is important for osmotic regulation in plants, it is not directly responsible for the opening and closing of stomata.
- **Potassium**: Potassium ions are essential for the regulation of stomatal movement. They help in the uptake of water by guard cells, leading to turgor pressure changes that open and close the stomata.
- **Phosphorus**: Phosphorus is mainly involved in energy transfer and nutrient movement within the plant, but it does not play a direct role in stomatal function.
- **Calcium**: Calcium is important for cell wall structure and stability, but it does not directly control the opening and closing of stomata.

4. **Determine the Correct Answer**: Based on the analysis, Potassium (option b) is the element that plays a significant role in the opening and closing of stomata.

5. **Conclusion**: Therefore, the correct answer to the question is **b. Potassium**.