What model of the solar system posits that the sun is at its center?

The heliocentric model of the solar system is based on the idea that the sun is at the center, and the planets, including Earth, revolve around it. This model was first proposed by the ancient astronomer Copernicus in the 16th century and marked a significant shift away from earlier models that placed Earth at the center, a belief known as the geocentric model.

The heliocentric model is supported by observations such as the changing positions of planets in the sky and the predictable patterns of their movements over time. With advancements in astronomical technology and understanding, this model has been validated through extensive evidence, including the laws of planetary motion formulated by Kepler and Newton's law of universal gravitation.

The other concepts—dynamic and static—do not describe models of the solar system specifically. Dynamic might refer to the motion of celestial bodies, whereas static would imply that the celestial bodies do not move in relation to each other, which is not representative of how the solar system operates. Hence, the heliocentric model remains the most accurate and widely accepted framework for understanding the arrangement and motion of the solar system's bodies.