The correct answer is:
b. removes pollutants or changes them chemically before they are released by factories.
Explanation:
1. A scrubber is a device used in factories to control air pollution.
2. It works by removing pollutants or altering them chemically before they are released into the atmosphere.
3. Scrubbers are important in reducing harmful emissions from industrial processes.
4. By using scrubbers, factories can minimize the environmental impact of their operations.
