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 one of the following is not an essential mineral element for plants, we need to analyze each option provided: iron, manganese, cadmium, and phosphorus.

### Step-by-Step Solution:

1. **Identify the Options**: The options given are:
- Iron
- Manganese
- Cadmium
- Phosphorus

2. **Understand Essential Mineral Elements**: Essential mineral elements for plants are those that are necessary for their growth and development. They play critical roles in various physiological processes.

3. **Analyze Each Element**:
- **Iron (Fe)**: An essential micronutrient that is crucial for chlorophyll formation and is involved in various enzyme functions, including peroxidases and catalases.
- **Manganese (Mn)**: Another essential micronutrient that activates enzymes involved in photosynthesis and nitrogen assimilation.
- **Phosphorus (P)**: A macronutrient that is vital for energy transfer (ATP), root development, and overall plant growth.
- **Cadmium (Cd)**: A heavy metal that is not essential for plant growth. Instead, it is toxic and can cause heavy metal toxicity in plants.

4. **Conclusion**: Based on the analysis, cadmium is not an essential mineral element for plants, while iron, manganese, and phosphorus are essential.

5. **Final Answer**: The correct answer is **Cadmium**.