A clinical trial is planned for AIDS patients to investigate whether a new treatment provides improved survival over the current standard treatment. It is not known if it will be better or worse. Researchers plan to use an experimental design, therefore the method they will use to assign patients to treatments in this experiment should be: assigning the healthiest subjects to the new treatment. O letting subjects choose which treatment they will receive. O assigning patients to treatments randomly. O assigning the least healthy subjects to the new treatment