Step 1: Understanding the Concept:
A food chain represents the flow of energy from one organism to another. It usually starts with producers (plants) followed by herbivores and then carnivores.
Grass: Producer (plants).
Deer: Primary consumer (herbivore).
Lion: Secondary/tertiary consumer (carnivore).
Step 2: Detailed Explanation:
Option (C) shows the correct food chain: plants (producers) → herbivores → carnivores. The other options are biologically incorrect (fish don’t eat grass, birds don’t eat snakes followed by grass, etc.).
Step 3: Final Answer:
The correct food chain is Grass $\rightarrow$ Deer $\rightarrow$ Lion.