E7D10

Why is a switching type power supply less expensive and lighter than an equivalent linear power supply?

1. AThe inverter design does not require an output filter circuit
2. BThe control circuitry uses less current, therefore smaller heat sinks are required
3. CThe high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
4. DIt recovers power from the unused portion of the AC cycle, thus using fewer components

Pick an answer to check it.