Final answer:
The (R) in the sequence Fredrick Lee, CRT, MRT, (R) ARRT stands for Registered.
Step-by-step explanation:
The (R) in the sequence Fredrick Lee, CRT, MRT, (R) ARRT indicates that the individual is registered for a specific profession. In this case, (R) stands for Registered and indicates that the person is registered with the American Registry of Radiologic Technologists (ARRT). This registration is a professional credential that demonstrates competency in radiologic technology.