Which LD50 value is representative of a highly toxic pesticide?

The LD50 value, which stands for "lethal dose for 50% of the population," is a critical measure used to indicate the toxicity of a substance, including pesticides. The lower the LD50 value, the more toxic the substance is. In the context of pesticide toxicity:

A value of 46 mg/kg indicates a high level of toxicity; it suggests that a relatively small dose can be lethal to half of the individuals exposed to it. This low dose reflects the potential for serious harm or death, establishing the pesticide as highly toxic.

Other values, such as 100 mg/kg, 250 mg/kg, and 500 mg/kg, indicate lower levels of toxicity compared to 46 mg/kg. As the numbers increase, the substance's toxicity decreases, meaning it takes a larger amount of the pesticide to reach the same lethal effect. Thus, these higher LD50 values are representative of less toxic substances relative to the selected answer.