Finish the following sentence with the best choice: How can you get rid of dust mites in pillows and bedding?

Choices:
- Airing out bedding is even more effective than washing when it comes to killing dust mites, reducing 95.1 percent of their numbers after an overnight stay in air.
- Freezing bedding is even more effective than washing when it comes to killing dust mites, reducing 95.1 percent of their numbers after an overnight stay in a freezer.

Answer:
Freezing bedding is even more effective than washing when it comes to killing dust mites, reducing 95.1 percent of their numbers after an overnight stay in a freezer.