Final answer:
Energy from the Sun's core is initially transported toward the convection zone through radiation and, subsequently, by convection once it reaches a certain point within the Sun.
Step-by-step explanation:
Energy is transferred from the core of the Sun toward the convection zone mainly in the form of radiation until it reaches about 70% of the distance from the center to the surface. At this point, convection takes over, transporting energy primarily by rising columns of hot gas. Inside the core, energy is generated through fusion, producing photons which engage in a process of absorption and reemission, known as radiation, facing high opacity within the Sun's interior. This makes the transportation of energy by radiation relatively inefficient until the convective zone is reached.