Overall, the Southern Hemisphere Has a Milder Winter Than the Northern

Overall, the Southern Hemisphere has a milder winter than the Northern Hemisphere because

A) the days are shorter in the Northern Hemisphere.
B) there is more water in the Southern Hemisphere.
C) ocean currents are almost non-existent in the Southern Hemisphere.
D) the Sun is closest to Earth during the Southern Hemisphere winter.
E) all of the above