In what solar system model was the sun proposed as the center of the solar system?
a. geocentric model
b. ptolemaic model
c. heliocentric model
d. none of the above

C. Heliocentric model

Explanation:

'Helios' in Greek means 'Sun' and 'centric' means at the 'center'. Thus, the solar system model where in sun was proposed to be at the center is the Heliocentric model. It was proposed by Nicolaus Copernicus. The sun is at the center of the solar system and the planets along with their moons revolve about it in circular orbits. Kepler described the laws of planetary motion where in the orbits are not circular but elliptical.

The geocentric model is also referred as Ptolemaic model. It considers Earth at the center of the solar system.