The term Milankovitch cycles most closely relate to periodic
changes in Earth’s orbit and angle of tilt relative to sun. So for this
question, the correct option is option “c”. Milankovitch affects actually deals
with the effect of the changes in the earth’s movements with the change in the
climatic conditions. Milankovitch was a Serbian geophysicist and also a great
astronomer. His studies actually helped in relating the climatic changes with
the changes in the tilt of the earth. He was the first person to mathematically
prove this situation.