## Core Concept
The question tests knowledge of side effects associated with anti-tubercular drugs, specifically focusing on the effect of transient memory loss. This requires understanding the pharmacological profiles of various drugs used in the treatment of tuberculosis.

## Why the Correct Answer is Right
The correct answer, , is associated with ethambutol not being correct; the drug known for causing transient memory loss or psychiatric side effects including confusion, is actually Cycloserine but more commonly and specifically is known for this side effect. However, among the given options, refers to a drug that can cause such neurological or psychiatric side effects. is known to cause a range of side effects due to its action on the nervous system.

## Why Each Wrong Option is Incorrect
* **Option A:** - This drug is primarily associated with hepatotoxicity and other side effects but not commonly with transient memory loss.
* **Option B:** - Ethambutol is known for its optic neuritis leading to visual disturbances but not typically transient memory loss.
* **Option D:** - While it has several side effects, transient memory loss is not a commonly highlighted or specific side effect associated with this drug.

## Clinical Pearl / High-Yield Fact
A key point to remember is that certain anti-tubercular drugs can have significant neurological or psychiatric side effects. For instance, can cause a range of neurological side effects, and awareness of these is crucial for managing patients on anti-tubercular therapy.

## Correct Answer Line
**Correct Answer: C.**