My Parents Are Aliens

Brian and Sophie find a huge Christmas tree. Without knowing how much energy it uses up, it threatens to blow up the spaceship. Eddie gets his confiscated Christmas present back and Jaq comes back home. Dan, Becky, Eddie and Jaq need to de-frost Brian and Sophie. After de-frosting them the meltdown only has 30 seconds left. Sophie's too frightened to press one of the four buttons and with three seconds left will the spaceship blow up or not? At the last second someone presses a button, but who is it and is it the wrong button??