The pyramid which cannot be inverted in a stable ecosystem is that of

Options

A. Biomass
B. Number of individuals
C. Energy
D. All of the above

Explanation

To solve the question regarding which pyramid cannot be inverted in a stable ecosystem, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Types of Pyramids**:
- There are three main types of ecological pyramids: pyramid of numbers, pyramid of biomass, and pyramid of energy. Each represents different aspects of an ecosystem.

2. **Identify Characteristics of Each Pyramid**:
- **Pyramid of Numbers**: This can be inverted in some ecosystems. For example, a single tree can support many insects, making the pyramid inverted.
- **Pyramid of Biomass**: This can also be inverted in certain cases, such as in aquatic ecosystems where the biomass of primary producers (like phytoplankton) can be less than that of primary consumers (like zooplankton).
- **Pyramid of Energy**: This is always upright. It represents the flow of energy through the trophic levels and shows that energy decreases as it moves up the food chain.

3. **Apply the 10% Law**:
- According to the 10% law, only about 10% of the energy is transferred from one trophic level to the next. This means that as you move up the pyramid, the amount of energy decreases significantly.

4. **Conclusion**:
- Since the pyramid of energy consistently shows a decrease in energy at each trophic level and cannot be inverted, it is the only pyramid that remains upright in a stable ecosystem.

5. **Final Answer**:
- The pyramid that cannot be inverted in a stable ecosystem is the **pyramid of energy**.