Final answer:
The National Committee for Clinical Laboratory Standards (NCCLS) is the organization that sets the national standards for phlebotomy procedures.
Step-by-step explanation:
The national organization that sets standards for phlebotomy procedures is the NCCLS, which stands for the National Committee for Clinical Laboratory Standards. Although the question provides alternative options such as ASCP (American Society for Clinical Pathology), NAACLS (National Accrediting Agency for Clinical Laboratory Sciences), and NCA (National Credentialing Agency for Laboratory Personnel), the NCCLS is the body that is primarily responsible for setting the standards for practices in clinical laboratories including phlebotomy. Medical professionals such as Medical Technologists (MT) and Medical Laboratory Technicians (MLT) often follow these procedures.