The correct answer is (a) Bronchoscopy
For explanation: Broncoscope is inserted in the body via the nasal passage and it used to image the respiratory tract. It has a very thin tube so that the patient feels minimal discomfort as the scope goes down the track. A laryngoscope can be used to examine the larynx. It is inserted through the mouth and the direction of the scope is changed at the epiglottis. This allows the scope to look at the larynx and not enter the GI tract.