Which of the following best describes anadromous fish?

Anadromous fish are species that are characterized by their unique life cycle that involves migrating from saltwater to freshwater to reproduce. This behavior allows them to take advantage of the nutrient-rich environments of freshwater rivers, which are often ideal for spawning. Once they reproduce in freshwater, the young fish typically develop in that environment before migrating back to the ocean.

Choosing the option that states they reproduce in freshwater and live in saltwater accurately reflects this biological pattern, as it highlights the migration habits that define anadromous fish. This life cycle is well-known in species such as salmon and sturgeon, which exemplify this migration cycle.

The other options do not accurately depict the life stages of anadromous fish, as they either misplace where reproduction occurs, where they live, or suggest habitats that are not typical for these fish. Therefore, the answer effectively encapsulates the essential characteristics of anadromous fish and their remarkable migratory behavior.