What is latitude? A. It is the distance between where you are and sea level.
B. It is the distance between the North Pole and the South Pole.
C. It is the distance east or west of the prime meridian.
D. It is the distance north or south from the equator.

What are the options?  

It's probably because the earth is actually tilted and is not straight when orbiting the sun. that's why when it's winter here, it's summer in the southern hemisphere. in the wintertime in the northern hemisphere, it's colder here because it's tilted away from the sun and the southern hemisphere is tilted closer to the sun (i believe this is the case anyways)