Traditionally, Child Psychology and Developmental Psychology Both Focused on the Behaviour

Traditionally, child psychology and developmental psychology both focused on the behaviour of children. One of many reasons for this interest is the fact that childhood is a period of rapid change. A reason NOT offered to account for this particular interest by the authors of your textbook is:

A) long-term influences
B) insight into complex adult processes
C) basic interest for the sake of increasing knowledge
D) interesting subject matter