Which of these is changed by the milankovitch cycles?

A: the length of a year on earth

B: the reflectivity of earth

C: the amount of solar energy that reaches earth

D: the duration of seasons on earth

Milankovitch studied changes in the movements of the Earth, which alter the amount and location of solar radiation reaching the Earth. This is known as solar forcing. So, the amount fo solar energy that reaches the Earth.

B

Explanation:

its known as eccentricity which is the shape of the earth's orbit. Over a time period of 100,000 years, the orbit ranges from being a nearly perfect circle to being an oval and back to a near-circle again.