Which phrase reflects your textbook's unifying theme of "heredity and environment jointly influence behaviour"

A)  man versus nature
B)  nature versus nurture 
C)  parent versus child
D)  biology versus psychology

Nature Versus Nurture

A debate concerning the relative importance of an individual's innate qualities ("nature") versus personal experiences ("nurture") in determining or causing differences in physical and behavioral traits.

Heredity

Heredity is the passing on of physical or mental characteristics genetically from one generation to another.

Environment

The surrounding conditions or influences that affect the growth, development, and survival of organisms, including humans.