E7D10: Why is a switching type power supply less expensive and lighter than an equivalent linear power supply?

Direct answer summary (2024-2028 NCVEC pool)

The official correct answer for E7D10 is The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output.

The reason is the high frequency inverter design uses much smaller transformers and filter components for an equivalent power output. Connect the cause in the question to this direct result instead of memorizing the answer letter.