How are X rays used in the technique of X-ray crystallography?

A) The scattering of X rays by a purified form of a molecule reveals its structure.
B) DNA strands are separated by X-ray energy, revealing the order of bases.
C) Cells are broken open to release chromosomes by being bombarded with X rays.
D) The X rays are used to mutate DNA, to determine the location of genes.
E) Enzymes are destroyed by X rays, revealing the order of steps in metabolism.