Final answer:
A sink food web is best described by '(c) One where all the connections lead to a top predator', representing how energy and nutrients are transferred towards the top of the ecosystem's trophic structure.
Step-by-step explanation:
The description that represents a sink food web is '(c) One where all the connections lead to a top predator'. In a sink food web, energy and nutrients flow toward the top predators which have few, if any, natural enemies. This is distinct from other food webs because top predators often govern the structure and population dynamics of the ecosystem by influencing the levels of species at lower trophic levels through predation.
Trophic levels in a food web can include primary producers like phytoplankton or plants, primary consumers which feed on those producers, secondary consumers which eat primary consumers, and so on up the trophic levels to the top predators. Unlike a linear food chain, a food web better represents the complex interactions within an ecosystem because it includes species that feed at multiple trophic levels and possess a variety of consumer roles.