Answer:
A) its elliptical orbit and tilt on its axis
Step-by-step explanation:
Earth revolves around the sun in an elliptical path. Its axis is tilted to about 23.5° from the vertical.
These two factors determine the global climate on the Earth.
Due to elliptical orbit, the earth is sometimes closer to sun than the rest of the time. When it is closer the global temperature rises by 5 degrees. Due to the tilt of the Earth, seasons occur. The hemisphere which points towards the sun has summers where as which points away has winters.
Thus, the long-term climate change is effected by elliptical orbit and tilt of the axis.