Question

which of the following filters are used in an air purifier?
pre - filter, biosand, ceramic filters
biosand filter, tds controller, activated carbon filter
hepa filter, ceramic filters, pre - filters
pre - filter, carbon filter, hepa filter

Explanation:

Pre - filters catch large particles, carbon filters remove odors and volatile organic compounds, and HEPA filters trap very fine particles. Biosand, ceramic filters, and TDS controllers are mainly used in water - purification, not air - purification.

Answer:

Pre - filter, Carbon filter, HEPA filter