Raven's Progressive Matrices require very little use of what?

Regarding the Big Five, most psychologists would probably agree with the statement that:

a. an individual's core traits change a lot throughout his or her lifetime. b. important traits involved in mental disorders are included in the Big Five. c. they only apply to people in western cultures, such as the United States and Great Britain. d. they lie at the core of key personality variations among individuals throughout the world.

Which of the following is another term used to describe independent variables (IVs)?

A) variations B) divisions C) levels D) factors