The follow picture shows the Earth and Moon (sizes not to scale relative to the distance between them. The Earth is about 100 times more massive than the Moon. The diagram also shows three positions of a hypothetical spaceship.

At which position is the combined force of gravity from the Earth and the Moon equal to zero?
    A ) A
    B) B
    C) C
    D) it is the same at all three positions

When called for, hold up the letter of your choice.