What device converts a vehicle's DC current into AC current?

The correct answer is the inverter. An inverter is specifically designed to convert direct current (DC) into alternating current (AC). This process is essential in various applications, such as providing power to devices that require AC power but are supplied with DC power from sources like batteries or solar panels.

Inverters work by using electronic circuitry to switch the current on and off rapidly, creating an AC output that can be used to power household appliances or vehicles that depend on AC electricity. This functionality makes them crucial in situations where DC power sources are prevalent, yet there’s a need for AC power, such as in renewable energy systems and portable generator setups.

The other options serve different purposes. A transformer is used to change the voltage level of AC current, not convert DC to AC. A converter generally refers to devices that can change power from one form to another, often focusing on voltage conversion or between AC and DC, but it does not specifically focus on the DC to AC conversion that an inverter specializes in. A generator typically creates AC power from mechanical energy but is not designed to convert existing DC power into AC.