Who is considered the predominant theorist in cognitive development?

Which of the following statements is true about the DSM–5?

A) It describes symptoms and includes information regarding the prevalence of specific disorders. B) It contains 12 specific "classifications" of mental illnesses. C) It is used to diagnose medical conditions that may have an impact on mental health. D) It is used to diagnose all kinds of medical conditions.

Expert chess players can automatically recognize 50,000 to 100,000 patterns, a level of skill that takes about how long to build up?

a. one year b. two years c. five years d. 10 years