Answer:
C. Both observation 1 and observation 2.
Explanation:
The heliocentric model states that the Earth and planets revolve around the Sun at the center of the Solar System.
Observation 1 was answered by Nicolas Copernicus, father of the heliocentrism, in 1543. The reverse effect is an illusion created because the Earth revolves faster around the Sun than Mars.
And observation 2 also is explained by the model because the rotation of the earth made that the Stars be closer to it at different times of the year.
I hope this answer helps you.
