Which of the following constitute a food-chain?

Explanation

To determine which of the given options constitutes a food chain, we need to understand the components of a food chain and how they interact. Here's a step-by-step solution to the question:

### Step-by-Step Solution:

1. **Understand the Definition of a Food Chain**:
- A food chain is a sequence of organisms where each is eaten by the next member in the chain. It starts with producers (autotrophs) and moves through various levels of consumers (herbivores and carnivores).

2. **Identify the Components of a Food Chain**:
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