Question

fish can be very pretty pets, but they need a lot more work than you might think. for one thing, you have to keep their water a certain temperature. also, many fish are sensitive to overfeeding. opinions differ on which fish is the prettiest. which detail supports the idea that pet fish take a lot of work? fish are pretty. fish need a specific water temperature. people disagree about the prettiest fish.

Explanation:

The text states that pet fish take a lot of work. One of the details given is that you have to keep their water at a certain temperature. This shows that there is effort involved in maintaining the right environment for the fish. The other options, "Fish are pretty" and "People disagree about the prettiest fish," do not relate to the work required for pet fish.

Answer:

Fish need a specific water temperature.