Answer:
B. Cilia and Mucus.
Step-by-step explanation:
The respiratory system uses cilia and mucus to filter the air we breathe. Cilia are tiny hair-like structures that line the air passages and help to move mucus and trapped particles out of the lungs. Mucus is a thick fluid that is produced by the lining of the air passages, and it serves as a trap for dirt, dust, and other particles that are inhaled. The cilia move the mucus and trapped particles up and out of the lungs, where they can be coughed or sneezed out of the body.