Please look at picture and help me.
(A) FB and DB
(B) HF and AC
(C) AC and FB
(D) DB and HF

Answer: D
Step-by-step explanation: Firstly, all the other answers make no sense, but you know it must be D because since it is a rectangular prism, the length from corner to corner on both sides is the same, so the lines are exactly on top of each other and the same size.