Cottle's test is used to diagnose-

Ans. is 'a' i.e., Deviated nasal septum o Cottle test: It is used to test nasal obstruction due to abnormality of nasal valve as in case of deviated nasal septumo In this test, cheek is drawn laterally while the patient breathes quietly. If the nasal airway improves on the test side, the test is positive, and indicates abnormality of the vestibular component of nasal valve.