Which factor is NOT included in the definition of a pesticide?

In defining what constitutes a pesticide, it is important to focus on the primary function and intention behind these substances. A pesticide is typically understood to be any material intended to kill, repel, or control pests. This includes substances specifically designed to eliminate pests or those that may attract them, as these actions directly relate to pest management.

Option C refers to products that regulate human health. While human health can be indirectly affected by pests or the pesticides used to control them, products specifically intended to manage human health are not classified as pesticides. Instead, they fall into different regulatory categories focused on health and safety, which are distinct from pest control measures.

Thus, the correct answer aligns with the understanding that while pesticides relate to pest control, those that solely regulate human health or promote plant growth do not fit within this definition.