Which of the milankovitch cycles changes the shape of the earth's orbit around the sun? a) eccentricity b) axial tilt c) precession d) rotation

Eccentricity.

Good luck!!

The answer you are looking for is A) Eccentricity

the path of the Earth's orbit around the sun is not a perfect circle, but an ellipse. This elliptical shape changes from less elliptical (nearly a perfect circle) to more elliptical and back, and is due to the gravitational fields of neighboring planets (particularly the large ones – Jupiter and Saturn).

Hope this helps

for the points