Which of the following is a key advantage of AC power over DC power?

AC power's key advantage lies in its ability to be transported over long distances more efficiently than DC power. This efficiency is primarily due to the use of transformers, which can easily step up the voltage of AC current for long-distance transmission. Higher voltage reduces the current flowing through the transmission lines, which minimizes energy loss due to resistance in the wires. When the AC reaches its destination, transformers can step the voltage down to safer levels for consumer use.

The other options present advantages that are not typically associated with AC power. For example, storing energy efficiently is more aligned with DC systems, such as batteries, which inherently store energy in a DC format. Additionally, while AC may be safer for some applications, it is not universally safer for all sensitive electronics compared to DC. Lastly, AC does not operate at consistently lower voltages than DC, as both types of power can be generated at various voltage levels depending on the application. Thus, the ability to transport power efficiently over long distances is what truly distinguishes AC power in this context.