How can a revolver be quickly reloaded?

Using a speed loader is the most efficient way to quickly reload a revolver. A speed loader is a device designed to hold multiple rounds of ammunition together, allowing the shooter to transfer them into the revolver's cylinder in one swift motion. This mechanism significantly reduces the time and effort needed compared to other methods of reloading.

Manual loading involves inserting each round into the revolver one by one, which can be time-consuming and cumbersome, especially under stress or in high-pressure situations.

Using a magazine is not applicable as revolvers do not utilize magazines; this is a feature commonly found in semi-automatic pistols.

Exchanging for a new revolver is not a practical or efficient method for reloading. While it may be a possibility in a hypothetical scenario, it does not constitute a standard or effective means of quickly reloading a revolver in real-life situations.

Therefore, employing a speed loader is the best option for quick reloading, making it the correct choice.