Which of the following is an ecosystem service?

• A. Pollination by bees.
• B. Fossil fuel production.
• C. Waste disposal by landfills.
• D. Noise pollution.

Answer: (A)

Ecosystem services are benefits humans receive from ecosystems. Pollination by bees is a classic example because it helps crops produce fruit and seeds, supporting food supply and agricultural economies. This benefit arises from the natural interactions of bees and plants and is directly useful to people, not something produced by human industry. The other options describe activities or effects that are not services ecosystems provide: producing fossil fuels is extracting resources, waste disposal by landfills is a human waste-management system, and noise pollution is a negative impact caused by disturbances. So, pollination by bees best fits as an ecosystem service.