The correct answer is option 2: 2 and 3.

Option 1: The use of livestock manure in agriculture can contribute to water pollution if it is not managed properly. When manure is spread on fields, it can wash into nearby water sources when it rains, carrying with it nutrients like nitrogen and phosphorous that can lead to nutrient pollution in water bodies. However, livestock manure alone is not primarily responsible for water pollution.

Option 2: The use of chemical fertilizers in agriculture is a major contributor to water pollution. Chemical fertilizers contain nutrients like nitrogen and phosphorous, which can leach into groundwater or runoff into rivers and lakes, causing nutrient pollution. This pollution can lead to harmful algal blooms, oxygen depletion, and damage to aquatic ecosystems.

Option 3: The excessive use of chemical pesticides in agriculture can also contribute to water pollution. Pesticides can be washed off fields during rainfall, contaminating nearby water bodies. These chemicals can harm aquatic organisms and disrupt the balance of ecosystems.

Option 4: Deforestation, although a harmful agricultural practice, is not directly responsible for water pollution. Deforestation can lead to soil erosion and changes in hydrological cycles, which can indirectly impact water quality. However, it is not a primary cause