There Are Half a Dozen Large Maria on the Side

There are half a dozen large maria on the side of the Moon facing Earth and only one small mare on the far side. Which of these explanations is the MOST likely?

A) Earth's larger mass attracted many heavy bombardment particles. Some of those that missed Earth hit the near side of the Moon.
B) Originally, there were probably as many large maria on the far side as on the near side, but subsequent bombardments erased most of them on the far side, while the near side was shielded from such bombardments by Earth's presence.
C) It is believed that the Moon was formed elsewhere in the solar system, so astronomers have no clue to its very early history-including this asymmetry in the maria.
D) The crust on the far side is thicker (because of Earth's pull on the Moon's core) , and thus it was more difficult for lava to flow into large craters on the far side.