Which of the Following Is True About Social Psychologists' Interest

Which of the following is true about social psychologists' interest in social problems?

A) Social problems are too complex to be addressed by social psychologists.
B) Interest in social problems has arisen only in the last decade.
C) Contemporary social psychologists are not interested in social problems.
D) Social problems have been a concern since the beginning of social psychology.
E) Generally, social psychologists cannot study social problems.