Amelia and Scott Are Assembling a Bunk Bed Set Together

Amelia and Scott are assembling a bunk bed set together. Amelia is reading the plans and tells Scott that the next part they need is an L shaped piece. Scott holds up a piece upside down and asks if it is the correct one. Amelia says he is holding it wrong so he turns it sideways. Assuming it is the correct piece, based on the research by Shepard and Metzler on mental rotation, for which orientation will Amelia find it easiest to recognize that the piece matches the picture in the instructions?

A) sideways and therefore oriented at 90 degrees
B) it depends on whether Amelia is right handed or left handed
C) both orientations will be of the same difficulty
D) upside down and therefore oriented at 180 degrees