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

**Step-by-Step Solution:**

1. **Understanding Essential Mineral Elements**: Essential mineral elements are those that are crucial for the growth and development of plants. They play vital roles in various physiological processes.

2. **Categories of Mineral Elements**: Mineral elements are classified into two categories:
- **Essential Elements**: These are necessary for plant growth and development. Examples include Iron, Magnesium, and Phosphorus.
- **Non-Essential Elements**: These are not crucial for growth; plants can survive without them, even if there is a deficiency.

3. **Identifying the Elements**: From the question, we need to identify which mineral element is not essential for plants. The essential elements mentioned include Iron, Magnesium, and Phosphorus.

4. **Analyzing the Options**: The question likely presents four options, three of which are essential minerals and one that is not. Based on the information provided, cadmium is highlighted as a non-essential element that is toxic to plants.

5. **Conclusion**: Therefore, the mineral element that is not essential for plants is **Cadmium**. It is toxic and inhibits important processes like photosynthesis and chlorophyll production.

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

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