一道语法,请指教

如题:

In his experiments with gravity, Issac Newton showed how the motion of each planet in the solar system results from the combined gravitational pull of the Sun and of all the other planets, each contributing according to their mass and distance from the others.

A.       of all the other planets, each contributing according to their

B.   of all the other planets, with each of them contributing according to their

C.       all the other planets, each of which contributing according to its

D.      all the other planets, each contributing according to its

E.     all the other planets, each of which contributing according to their

我以为D比较好,但是也有人说B对.请各位多多指点.非常感谢!

我同学拿给我做的.

我认为是D,他却说B对.因为后面用的是others,所以他认为前面应该用their而不是its.

i choose D,