Two species that do not interact at all have what type of interaction?

The correct answer is "Neutral" because in ecological terms, when two species do not interact at all, it means that their presence or absence has no effect on each other. This non-interaction can lead to a neutral relationship, wherein neither species benefits nor is harmed by the other.

In contrast, the other options involve some form of interaction. Symbiotic interactions involve close relationships between species, which can be either beneficial or harmful. Competitive interactions occur when two species vie for the same resources, leading to negative effects on at least one species. Predatory interactions are characterized by one species preying on another, resulting in direct harm to the prey species. Thus, when there is no interaction, the term that best describes such a scenario is neutral, making it the appropriate choice.