Psychologists who have studied the development of self-concept over the lifespan have found that the self-concept starts out and gradually becomes with increasing age.
a. extremely positive; more realistic
b. concrete; more abstract and complex
c. extremely negative; more positive
d. individually focused; socially focused

Psychology may be defined as the branch of science that mainly deals with the behavior, understanding and mental situation of the individual. The psychologist who is expertise in the field of psychology.

The psychologist studies different methods and concept in psychology. The concept of the self start of an individual is generally concrete and quite complex. But later on this concept becomes more complex and more abstract is included in this stage.

Thus, the correct answer is option (b).