Which one of the following is not an essential mineral element for plants while the remaining three are?

Options

A. Iron
B. Manganese
C. Cadmium
D. Phosphorus

Answer

To determine which of the following is not an essential mineral element for plants, we need to analyze each option: Iron, Magnesium, Cadmium, and Phosphorus.

### Step-by-Step Solution:

1. **Identify Essential Mineral Elements**:
- Essential mineral elements are those that are crucial for plant growth and development. Examples include Iron, Magnesium, Phosphorus, Potassium, and Nitrogen.

2. **Evaluate Each Option**:
- **Iron**: This is an essential element that plays a vital role in chlorophyll synthesis and is crucial for photosynthesis.
- **Magnesium**: This is also essential as it is a core component of chlorophyll and is important for various enzymatic reactions in plants.
- **Phosphorus**: This is essential for energy transfer (ATP), nucleic acids, and overall plant growth.
- **Cadmium**: This is not an essential element for plants. In fact, it is considered toxic and can inhibit plant growth by affecting photosynthesis and chlorophyll production.

3. **Conclusion**:
- Among the options provided, Cadmium is the only one that is not an essential mineral element for plants. Therefore, the answer is Cadmium.

### Final Answer:
Cadmium is not an essential mineral element for plants.

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