Two children float motionlessly in a space station. The $20-$kg girl pushes on the $40-$kg boy and he sails away at $1\mathrm{.}0$ m$/$s$.$ The girl

Group of answer choices

moves in the opposite direction at $2\mathrm{.}0$ m$/$s$.$

moves in the same direction at $1\mathrm{.}0$ m$/$s$.$

remains motionless.

moves in the opposite direction at $1\mathrm{.}0$ m$/$s$.$

moves in the same direction at $2\mathrm{.}0$ m$/$s$.$