Question

how can agriculture contribute to water pollution?
reduced algal blooms
pesticide and fertilizer runoff
planting monocultures
too little irrigation

Explanation:

To determine how agriculture contributes to water pollution, we analyze each option:

• "Reduced algal blooms" would decrease pollution, not cause it.
• "Pesticide and fertilizer runoff" occurs when rain or irrigation washes these chemicals from farmland into water bodies, introducing pollutants like excess nutrients (from fertilizers) and toxic substances (from pesticides), which is a major source of agricultural water pollution.
• "Planting monocultures" relates more to biodiversity loss and soil health issues, not direct water pollution.
• "Too little irrigation" affects crop growth but not water pollution directly.

Answer:

B. pesticide and fertilizer runoff