The correct answer would be we have no other frame of reference besides the sky. We could actually tell we are moving because of the shifting of stars in the sky over time. But really, “A” would be your answer. We have the same momentum of the earth. It’s like being on a train at a constant speed. The only way you know you’re moving is if you look out the window or the speed changes causing you to be pushed around. Same thing with earth, our only reference is the sky
