The correct answer is: B. A set of interconnected food chains, illustrating the tropic relationships among species.
A food chain is a linear sequence of organisms through which nutrients and energy pass in an ecosystem. A food web is a more complex system of interconnected food chains. In a food web, each organism is connected to several other organisms, either as a predator or as a prey. This means that the energy and nutrients in a food web are more evenly distributed than in a food chain.
Option A is incorrect because a food web is not like a food chain. A food chain is a linear sequence of organisms, while a food web is a more complex system of interconnected food chains.
Option C is incorrect because the set of prey species that are consumed by animals in an ecosystem is not a food web. A food web is a more complex system of interconnected food chains.
Option D is incorrect because the tropic (feeding) levels that can be observed in an ecosystem are not a food web. A food web is a more complex system of interconnected food chains.