Piaget Asserted That the Child's Experiences in the World, in Combination

Piaget asserted that the child's experiences in the world, in combination with maturation, together influence the child's cognitive development. This assertion BEST reflects the unifying theme in psychology that

A) psychology evolves in a socio-historical context.
B) heredity and environment jointly influence behaviour.
C) psychology is theoretically diverse.
D) our experience of the world is highly subjective.