Answer: C. Inhalation
Step-by-step explanation:
Drugs administered in the body through inhalation through nostrils can be taken in the form of small droplets. These are taken to the nasal route so that the drug can enter into the windpipe and then finally into the lungs. This way the drug directly enters into the respiratory system and then finally absorbed to the blood stream.
The drug administration through this way irritates the respiratory tract and causes diseases related to the respiratory system. For example, drugs like opioids, may cause labored breathing and makes the symptoms of the asthma worse.