The Sun transfers heat to Earth by

Conduction is the transfer of heat through direct contact between materials, requiring a medium such as solid, liquid, or gas. Since space is a vacuum and there is no direct contact between the Sun and the Earth, conduction cannot be the mechanism by which the Sun transfers heat to our planet.

Ionization refers to the process of converting atoms or molecules into ions by adding or removing charged particles, typically electrons. While ionization occurs in the Sun's atmosphere and can affect solar wind, it does not pertain to the transfer of heat to Earth. Therefore, it is not a relevant mechanism for this question.

Sublimation is the transition of a substance from solid to gas without passing through a liquid state. This process is not related to the transfer of heat from the Sun to the Earth. Sublimation occurs in specific materials under certain conditions, but it does not pertain to the mechanism of solar heat transfer.