The correct answer is option 3 - "passage of food (and thus energy) from one organism to another."

A food chain is a sequence of organisms, where each organism consumes the one below it and is then consumed by the organism above it. It represents the flow of energy in an ecosystem.

Option 1 - "relationship between autotrophic" is not the correct answer because while autotrophs play a crucial role in the food chain as primary producers, the food chain encompasses both autotrophs (organisms that produce their own food) and heterotrophs (organisms that obtain food by consuming other organisms).

Option 2 - "exchange of genetic material between two organisms" is not the correct answer because a food chain is not related to genetic material exchange, but rather the transfer of energy through the consumption of food.

Option 4 - "modern entrepreneur establishment providing food outlets" is not the correct answer because it does not accurately describe a food chain. It refers to a business establishment rather than the ecological concept of a food chain.

In summary, option 3 is the correct answer as it accurately represents the concept of a food chain involving the passage of food and energy from one organism to another.