Deficiency symptoms of an element tend to appear first in young leaves. It indicates that the element is relatively immobile. Which one of the following elemental deficiency would show such symptoms?

Options

A. Sulphur
B. Magnesium
C. Nitrogen
D. Potassium

Explanation

To solve the question regarding which elemental deficiency would show symptoms first in young leaves, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question states that deficiency symptoms of an element appear first in young leaves, indicating that the element is relatively immobile.

2. **Identify the Elements**: The options provided are sulfur, magnesium, nitrogen, and potassium. We need to determine which of these elements is relatively immobile.

3. **Define Mobility in Nutrients**: In plants, the mobility of nutrients affects where deficiency symptoms appear. If a nutrient is mobile, deficiency symptoms will show up first in older leaves because the plant can relocate the nutrient from older to younger tissues. Conversely, if a nutrient is immobile, deficiency symptoms will appear first in the younger leaves since the nutrient cannot be moved from older tissues.

4. **Analyze Each Element**:
- **Sulfur**: Generally considered immobile; deficiency symptoms appear first in young leaves.
- **Magnesium**: Mobile; deficiency symptoms typically appear in older leaves.
- **Nitrogen**: Mobile; deficiency symptoms typically appear in older leaves.
- **Potassium**: Mobile; deficiency symptoms typically appear in older leaves.

5. **Conclusion**: Based on the analysis, sulfur is the element that shows deficiency symptoms first in young leaves, indicating its immobility.

### Final Answer:
The elemental deficiency that would show symptoms first in young leaves is **sulfur**.

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