Which of the following is a primary way humans cause thermal pollution?

• A. Adding fertilizers to agricultural fields
• B. Discharging heated water from power plants into rivers and lakes
• C. Burning fossil fuels in vehicles
• D. Using solar panels to generate electricity

Answer: (B)

Verified step by step guidance

1. Understand the concept of thermal pollution: it refers to the degradation of water quality by any process that changes ambient water temperature, often making it warmer than normal.
2. Identify human activities that can increase water temperature directly, such as releasing heated water into natural water bodies.
3. Evaluate each option: adding fertilizers affects nutrient levels (eutrophication), burning fossil fuels releases gases but does not directly heat water, and solar panels generate electricity without heating water.
4. Recognize that power plants often use water as a coolant and then discharge this heated water back into rivers or lakes, raising the temperature of these water bodies.
5. Conclude that discharging heated water from power plants into rivers and lakes is the primary way humans cause thermal pollution.