Why do the stars and the constellations in the sky appear to change positions throughout the night and throughout the year?

Question

a The earth's tilt changes its positions relative to the stars and constellation only because the Earth rotates around its axis
b The earth's tilt changes it position relative to the stars and constellation as the Earth rotates the orbits
c The location angle of the Earths tilt relative to stars and constellation remains the same throughout the year
d The stars and constellation have tilted and are also moving in space

Answer 1

a The earth's tilt changes its positions relative to the stars and constellation only because the Earth rotates around its axis.