Which of the following human activities is most likely to lead to groundwater pollution?

Agriculture is most likely to lead to groundwater pollution due to several practices commonly associated with it. The use of fertilizers and pesticides in farming introduces various chemicals into the soil. When it rains or through irrigation practices, these substances can leach into the soil and eventually make their way into the groundwater supply.

Additionally, agricultural runoff, which may contain animal waste, pesticides, and fertilizers, can significantly contaminate nearby water bodies and possibly infiltrate groundwater systems. The concentration of these pollutants in agricultural areas is often much higher than in areas with the other activities listed. Consequently, the scale and intensity of agricultural operations directly contribute to the risk of groundwater pollution.

In contrast, recreational fishing, urban gardening, and wildlife conservation generally do not involve the use of harmful chemicals on the same scale, making them less likely to cause groundwater contamination. While any human activity can potentially impact water quality, the practices typical in agriculture pose a greater and more widespread risk to groundwater resources.