You are standing upright in a room in front of a vertical mirror. In this mirror, you can see from your position, only the upper two-third part of your body. You wish to see the full image of your body in the mirror. Which combination of the following three courses of action will achieve this?
I. Move away from the mirror
II. Move towards the mirror
III. Use a mirror whose height will allow you to see your full image
A I only
B II only
C III only
D Either I or III
How come it is only option C and not D ?