This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Prolonged administration of streptomycin may result in damage to the: 
Select and explain. 
A. Optic nerve, B. Facial nerve, C. Auditory nerve, D. Trigeminal nerve
C: Auditory nerve
Answer: C: Auditory nerve 
Explanation: Streptomycin (antitubercular) causes vestibular damage on prolonged use.
Adverse effects

This class of drugs is notorious for their adverse effects like ototoxicity and nephrotoxicity.
About 1/5th patients given streptomycin 1 gm BD i.m. experience vestibular disturbances although auditory disturbances are less common. 
Streptomycin has the lowest nephrotoxicity among aminoglycosides; probably because it is not concentrated in the renal cortex.

Reference: Essentials of Medical Pharmacology Eighth Edition KD TRIPATHI page no 94,798