which of the following statements best describes how molecules released by the fish become nutrients for the plants?

Molecules released by the fish become nutrients for the plants because decomposers and bacteria chemically change the fish waste into simple, usable molecules (like nitrates and phosphates) that plant roots can absorb.

In other words, it works like this in most ecosystems or aquaponic tanks:

1. Fish release waste (ammonia and other organic molecules) into the water.

2. Beneficial bacteria and other microorganisms break this waste down into simpler, dissolved nutrients such as nitrates and phosphates.

3. Plants take up these dissolved nutrients through their roots and use them to build new tissues (leaves, stems, roots, etc.).

So, if you are choosing among options, the best statement will be the one that says that bacteria/microorganisms convert molecules released by the fish into simpler dissolved nutrients that plants can absorb and use for growth , not that plants directly “eat” fish or their waste.