Ebbinghaus is important for the history of psychology because he ____.?

a. ?used reaction times to measure the speed of recalling information from memory
b. ?wrote the first definitive work on child psychology
c. ?successfully challenged Wundt's claim that higher mental processes, such as learning and memory, could not be studied in the laboratory
d. ?united with Gestalt psychology to oppose the spread of Wundt's psychology in Germany
e. ?taught Freud and influenced humanism and Gestalt psychology

c