Assertion: In Terrestrial, ecosystem much larger fraction of energy flows through the detritus food chain
Reason: In an aquatic ecosystem. GFC is the major conduit for energy flow.

Options

A. If both Assertion `&` Reason are True `&` the Reason is a correct explanation of the Assertion.
B. If both Assertion `&` Reason are True but Reason is not a correct explanation of the Assertion
C. If Assertion is True but the Reason if False.
D. If both Assertion `&` Reason are false.

Answer

To solve the assertion-reasoning question, we need to analyze both the assertion and the reason provided.

### Step 1: Analyze the Assertion
The assertion states: "In terrestrial ecosystems, a much larger fraction of energy flows through the detritus food chain."

- **Explanation**: In terrestrial ecosystems, the detritus food chain plays a significant role in energy flow. This chain includes the decomposition of organic matter (like dead plants and animals) and the organisms that feed on this matter (detritivores). The energy from the organic matter is transferred through various levels of consumers, making this food chain a crucial pathway for energy flow in terrestrial environments.

### Step 2: Analyze the Reason
The reason states: "In an aquatic ecosystem, the grazing food chain (GFC) is the major conduit for energy flow."

- **Explanation**: In aquatic ecosystems, the grazing food chain is indeed the primary pathway for energy transfer. This food chain involves primary producers (like phytoplankton) being consumed by primary consumers (like zooplankton), and this process continues up the food chain. Therefore, the reason is also correct.

### Step 3: Determine the Relationship
Now we need to determine if the reason correctly explains the assertion.

- **Comparison**: Both the assertion and reason are true statements. However, they refer to different ecosystems (terrestrial vs. aquatic). The assertion discusses energy flow in terrestrial ecosystems, while the reason discusses energy flow in aquatic ecosystems.

### Conclusion
Since both statements are true but the reason does not explain the assertion, the correct answer is:
**Both assertion and reason are true, but the reason is not a correct explanation of the assertion.**