Which method describes radiation in terms of heat transfer?

Radiation is defined as the transfer of heat in the form of electromagnetic waves, which can travel through a vacuum and does not require any medium such as air or a solid to facilitate the transfer. This characteristic distinguishes radiation from other heat transfer methods that rely on direct contact or the movement of fluids.

The correct answer highlights that radiation enables heat transfer without needing to heat the air or any other medium between the source of heat and the object absorbing that heat. This is why it can occur in spaces where there are no direct connections or physical contacts—such as the warmth felt from the sun standing in an open area.

Understanding radiation in this context is crucial for applications ranging from thermal insulation design to energy efficiency in buildings, where improving or controlling heat loss via radiation can significantly impact energy consumption and comfort.