Selectivity in pesticides refers to their effectiveness on:

Selectivity in pesticides pertains specifically to their effectiveness in targeting one or a limited number of pest species while having minimal impact on non-target organisms. This characteristic is essential for integrated pest management strategies, as it allows for the control of harmful pests while preserving beneficial insects and other wildlife, as well as minimizing risks to humans and pets. A selective pesticide can reduce the risk of disrupting the overall ecosystem and helps in managing pest populations without causing collateral damage to other species.

In contrast, other options do not align with the concept of selectivity. Pesticides that affect all pest species would be considered broad-spectrum, which can lead to unintended consequences in the ecosystem. Human beings and pets are generally not the intended targets of pesticides, and thus, selectivity is not defined by their effects on these groups. Weeds can be specifically targeted by herbicides but are not limited to pests in the traditional sense, as selectivity focuses more on pests that harm crops or impair ecological balance.