Which of the Following Describes a Developmental Psychologist

Which of the following describes a developmental psychologist?

A) Dr.Smith who conducts research in areas such as learning,memory,thinking,and motivation
B) Dr.Jones who studies changes in the way people think,how they relate to others,and how people feel throughout their lives
C) Dr.Baker who studies how people are affected by the presence of other people
D) Dr.Peterson who focuses on the study of the biological basis of behavior