Answer: A) D and H
These two points are on the front panel along with points A and B
Choice B is not the answer since points A,B,F are on the floor panel, but point I is not on the floor panel (instead its on the right wall panel)
Choice C is not the answer as points G and C are in the ceiling panel, while A and B are in the floor panel and front wall panel.
Choice D is not the answer for similar reasoning as choice B not being the answer.
Points are considered coplanar if they are in the same plane. A plane can be thought of as a flat piece of paper that does not bend or curve.