In the Grid Method of Bloodstain Documentation, a Grid of Squares

In the grid method of bloodstain documentation, a grid of squares of known dimensions is created over an entire pattern in order to:

A) prevent contamination of the bloodstains.
B) collect bloodstains for delivery to the laboratory.
C) show the relative sizes of bloodstains in photographs.
D) all of the above.
E) none of the above.