Final answer:
The least hazardous pesticides are labeled with the signal word 'Caution' and the precautionary statement 'Keep out of reach of children', signifying the minimal level requirement for pesticide labels.
Step-by-step explanation:
The minimal level signal word and warning statement that must be on pesticide labels is D. The signal word “Caution” and “Keep out of reach of children”.
Pesticide labels are regulated to ensure safety and inform users of the potential hazards associated with pesticide use. The signal words used on these labels range from “Caution”, indicating the lowest level of toxicity, to “Warning”, and up to “Danger” for the most toxic substances.
In addition to signal words, precautionary statements such as “Keep out of reach of children” are required to prevent accidental poisoning and to ensure that these substances are handled properly by users.