Developmental scientists are:
a. primarily researchers.
b. primarily practitioners.
c. primarily psychologists.
d. researchers and practitioners from a variety of disciplines.

d. researchers and practitioners from a variety od disciplines.

Explanation:

They are synthesising perspectives from biology, psychology, and sociology to understand behavioral and psychological aspects of human development.

answer is no d as developmental scientists are related to the development of children psychology and also they research about their adultsaction on making the psychology better. they study the psychological aspect of human development. and it is an interdisciplinary subject too .

hope it helps.

answer; i believe that the correct answer is rapid and subsequently slow down;