In a food chain, the trophic levels are as follows:
- First trophic level: Producers (e.g., plants, algae)
- Second trophic level: Primary consumers (e.g., herbivores)
- Third trophic level: Secondary consumers (e.g., carnivores, omnivores)
- Fourth trophic level: Tertiary consumers (e.g., apex predators)
If a man eats fish, the fish is typically a secondary consumer (as it feeds on primary consumers like smaller organisms). Therefore, the man occupies the third trophic level in the food chain.
Final Answer:
\[
\boxed{\text{The correct answer is (3) Third.}}
\]