**Core Concept**
The management of Multidrug-Resistant Tuberculosis (MDR-TB) involves the use of a combination of drugs, including second-line agents, to treat patients who are resistant to first-line anti-tuberculosis medications such as isoniazid and rifampicin. The choice of drug depends on the specific resistance pattern of the isolate.

**Why the Correct Answer is Right**
Ethambutol is a first-line anti-tuberculosis medication used to treat drug-susceptible TB. It is not typically used in the treatment of MDR-TB due to the risk of optic neuritis, which can be irreversible. In contrast, second-line agents such as aminoglycosides (e.g., amikacin, kanamycin), polypeptides (e.g., capreomycin), and fluoroquinolones (e.g., moxifloxacin, levofloxacin) are commonly used to treat MDR-TB.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not provided, so we cannot evaluate it.
* **Option B:** This option is not provided, so we cannot evaluate it.
* **Option C:** This option is not provided, so we cannot evaluate it.
* **Option D:** This option is not provided, so we cannot evaluate it.

**Clinical Pearl / High-Yield Fact**
The use of first-line anti-tuberculosis medications, including ethambutol, in MDR-TB treatment can lead to treatment failure and the development of further resistance. Second-line agents should be used in conjunction with first-line agents that are still susceptible to the isolate.

**Correct Answer:** Not Provided