What limitation applies to most theoretical systems of personality?

A) Personality has proven to be impossible to measure.
B) No personality system can capture all the unique differences among people.
C) It has been difficult to identify a core set of personality dimensions.
D) Personality is, by definition, an unconscious process.

Most theoretical systems of personality have a limitation in that they cannot capture all the unique differences among people. Each person is unique, and it is nearly impossible to create a system that can account for all of the different factors that contribute to a person's personality. While different systems may be able to capture certain aspects of personality, they cannot account for everything.