What Was the Main Contribution of Hermann Ebbinghaus to Psychology

Multiple Choice

What was the main contribution of Hermann Ebbinghaus to psychology?

A) He demonstrated that mental elements were more important than the concept of Gestalt.
B) He established the first scientific laboratory for the study of conscious processes.
C) He emphasized that the whole is greater than the sum of its parts.
D) He demonstrated that carefully controlled experimentation can be conducted.