I think that if you are very sure of your answer, A is a good choice. So is B in that case. Before anything is entered into a crime journal it must be accepted as a legal procedure in the practice of criminal law. Or it must be a discussion on why it cannot be used as evidence.
That only leaves D. Examination of Questionable Documents is another way of saying Forgery. Forensic Chemistry is something only found in the lab, and it takes highly skilled technicians to make use of this tool. DNA is definitely something you would do in a lab. No Lawyer could ever process DNA unless he was first a biochemist before becoming a lawyer. If I had to answer the question, I would pick D, but it you like A better, go with it.
Answer: D