The plant ash is an indication of

Options

A. Organic matter of plant
B. Waste product
C. Mineral salts absorbed by plants
D. None of these

Answer

### Step-by-Step Solution:

1. **Understanding Plant Ash**: Plant ash is the residue that remains after a plant is subjected to high temperatures. This process involves burning the plant material until all organic matter is incinerated, leaving behind inorganic residues.

2. **Differentiating Fresh Weight and Dry Weight**: The weight of a plant can be categorized into two types:
- **Fresh Weight**: This includes the weight of water and protoplasm in the plant.
- **Dry Weight**: This is the weight of the plant after all water has evaporated, representing only the mass of the protoplasm.

3. **Heating to Obtain Plant Ash**: When the dry weight of the plant is further heated to extremely high temperatures, it results in the formation of plant ash. This ash consists of the inorganic components that were present in the plant.

4. **Indication of Minerals**: The plant ash is primarily composed of mineral salts that were absorbed by the plant from the soil. Therefore, the presence of plant ash indicates the types and amounts of minerals that the plant has taken up during its growth.

5. **Conclusion**: Thus, the final answer is that plant ash is an indication of the mineral salts absorbed by plants.

### Final Answer:
The plant ash is an indication of mineral salts absorbed by plants.

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