Assertion: No energy that is trapped into an organism remains in it for ever.
Reason: The energy trapped by the producer is either passed on to a consumer or the organism dies.

Options

A. If both assertion and reason are true and the reason is a correct explanation of the assertion.
B. If both assertion and reason are true but reason is not a correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "No energy that is trapped into an organism remains in it forever." This means that energy is not permanently stored in any organism.

2. **Analyzing the Energy Flow**:
- In an ecosystem, energy flows through different trophic levels. It starts with producers (like plants) that capture solar energy through photosynthesis.

3. **Energy Transfer Between Trophic Levels**:
- As energy moves from one trophic level to the next (from producers to primary consumers, and so on), only about 10% of the energy is transferred to the next level. The rest is lost as heat or used for metabolic processes.

4. **Understanding the Reason**:
- The reason states that "The energy trapped by the producer is either passed on to a consumer or the organism dies." This indicates that energy does not remain in the producer indefinitely; it is either utilized by consumers or lost when the organism dies.

5. **Conclusion**:
- Both the assertion and the reason are true. The reason correctly explains the assertion because it clarifies how energy is transferred and why it does not remain in an organism forever.

### Final Answer:
- Both assertion and reason are true, and the reason is the correct explanation of the assertion. Therefore, the correct option is **Option 1**.