Select the correct statement regarding manganese toxicity.

Options

A. Appearance of brown spots surrounded by chlorotic veins
B. inhibition of Ca translocation in shoot apex
C. induction deficiencies of Mg and Fe
D. all of these

Explanation

**Step-by-Step Solution:**

1. **Understanding Manganese Toxicity**: Manganese toxicity occurs when the concentration of manganese in plants exceeds the desired amount, leading to harmful effects on plant health.

2. **Effects of Manganese Toxicity**: When manganese levels are too high, it competes with essential nutrients such as iron, magnesium, and calcium. This competition inhibits the uptake of these nutrients from the soil.

3. **Deficiency Symptoms**: The inhibition of iron and magnesium uptake leads to deficiencies of these elements in plants. Additionally, manganese toxicity also affects calcium by inhibiting its translocation to the shoot apex (the growing tip of the plant).

4. **Chlorosis and Other Symptoms**: One of the visible symptoms of manganese toxicity is chlorosis, which is characterized by yellowing of the leaves, particularly in the veins. This may also be accompanied by the development of brown spots around the chlorotic veins.

5. **Evaluating the Options**:
- **Option 1**: Appearance of brown spots surrounded by chlorotic veins - This is correct.
- **Option 2**: Inhibition of calcium translocation to the shoot apex - This is also correct.
- **Option 3**: Induction of deficiencies of magnesium and iron - This is correct as well.
- **Option 4**: All of these - Since all the previous statements are correct, this option is also correct.

6. **Conclusion**: The correct statement regarding manganese toxicity is "All of these," as all the effects mentioned in the options are valid consequences of manganese toxicity in plants.