Final answer:
The Pharmacy Technician Certification Board (PTCB) offers national certification for pharmacy technicians through the PTCE exam. The NHA also offers certification via the ExCPT exam.
Step-by-step explanation:
The organization that offers national pharmacy technician certification by exam is the Pharmacy Technician Certification Board (PTCB). To achieve this certification, candidates must pass the Pharmacy Technician Certification Exam (PTCE). Another organization that also offers a certification exam for pharmacy technicians is the National Healthcareer Association (NHA) with its ExCPT exam. Please note that neither the Distance Education Accrediting Commission (DEAC) nor the Food and Drug Administration (FDA) offer certifications for pharmacy technicians, and 'PTA' is likely a typographical error and does not correspond with a recognized certifying body in this context.