In What Way Has the Psychological Study of Concepts Changed

Multiple Choice

In what way has the psychological study of concepts changed over the years?

A) It hasn't: same old, same old.
B) Psychologists have increasingly focused on concepts that can be clearly defined by simple rules.
C) Psychologists have turned increasingly to the study of more ambiguous but more relevant concepts.
D) Psychologists have largely abandoned the study of concepts as irrelevant to day-to-day concerns.