**Core Concept**
The initial mechanism of action of intra-tympanic gentamicin in the treatment of Meniere's disease involves the disruption of the vestibular function by targeting the hair cells within the inner ear. Gentamicin is an aminoglycoside antibiotic that acts by inhibiting protein synthesis in bacteria, but in this context, it is used to induce vestibular ablation.

**Why the Correct Answer is Right**
Intra-tympanic gentamicin works by entering the inner ear through the round window membrane, where it is absorbed by the hair cells. The aminoglycoside antibiotic then binds to the bacterial 30S ribosomal subunit, inhibiting the initiation complex formation and thus preventing the translation of messenger RNA into protein. This action ultimately leads to the death of the hair cells, which are responsible for the vestibular function in the inner ear. The vestibular function is disrupted, providing relief from the symptoms of Meniere's disease.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because intra-tympanic gentamicin does not act by reducing inflammation in the inner ear.

**Option B:** This option is incorrect because gentamicin does not work by reducing the production of inner ear fluid.

**Option C:** This option is incorrect because gentamicin does not act by stimulating the auditory nerve.

**Option D:** This option is incorrect because gentamicin does not work by reducing the symptoms of Meniere's disease through a central mechanism.

**Clinical Pearl / High-Yield Fact**
It is essential to note that the use of intra-tympanic gentamicin should be approached with caution, as it can cause vestibular toxicity and ototoxicity. A thorough evaluation of the patient's hearing and vestibular function is necessary before and after the procedure to minimize the risk of adverse effects.

**Correct Answer:** C.