Titchener's Most Important Publication Was a Series of Four Books

Titchener's most important publication was a series of four books, commonly called the "Manuals." These books were important because they

A) were the definitive statement of his structural psychology
B) addressed the four principal areas of applied psychology that Titchener pioneered
C) were used to train a generation of American psychologists in research methods
D) provided a theoretical account relating the elements of consciousness to their underlying physiological processes