The correct answer is A. Pollution
Step-by-step explanation:
In ecology, an abiotic factor refers to a factor that is non-living but still affects the living organisms of an ecosystem; additionally, an abiotic limiting factor refers to an abiotic factor that limits or stops the growth of organisms in an ecosystem. This implies, in the case of a pond ecosystem the one that is an abiotic limiting factor of fish is pollution, because this factor is the only one that can be completely classified as non-living because food, disease, and predators are living factors or biotic factors. Besides this, pollution can limitate or stop the population of fish to grow or thrive which also makes pollution a limiting factor.