When Photographing a Crime Scene, It Is Important That an Object

When photographing a crime scene, it is important that an object of known size be included within the frame of the picture. This can be accomplished by

A) placing a ruler next to the object being photographed.
B) placing a coin next to the object being photographed.
C) placing a person next to the object.
D) Both choice a and b are correct.
E) Choices a, b, and c are correct.