Which type of psychologist is concerned with changes in behaviour throughout the life span

A)  a social psychologist
B)  a developmental psychologist 
C)  a personality psychologist
D)  a cognitive psychologist

Developmental Psychologist

A psychologist who specializes in understanding the changes that people undergo throughout their lifespan, including physical, cognitive, social, intellectual, perceptual, personality, and emotional growth.

Behaviour

The actions or reactions of an organism, often in relation to its environment, which can be observed and measured.

Life Span

The maximum duration of life, or the length of time an individual or entity exists from birth to death.