Answer:C. It focused on a cognitive process—mentally converting the stimulus—at a time when most psychologists focused on people's external behavior.
Explanation:George A. Miller was a psycholigist working in Harvard university,he stated a law sometimes called the Miller Law,where he stated that the average human memory can be able to hold in a short-term memory of 7 ± 2 number of data,this is one of the most sites psychological theories.
George A. Miller(1956) focused his work on the cognitive process making it unique and special compared to other psycholigist who focused on external Behaviors.