The nursing instructor is discussing the use of nasal decongestants and shares what reason for their effectiveness?

They come into direct contact with nasal mucosa.

Explanation:

Nasal decongestants may be defined as the chemicals that might works against the congestion occurs in the nose, chest and in the sinuses. Congestion might result in the swelling of blood vessels.

The nasal decongestants narrows the blood vessels and might result in the decrease in the inflammation and swelling. These nasal decongestants are quite effective as they are in the direct contact with the layers of the nasal mucosa.

Thus, the answer is they come into direct contact with nasal mucosa.