Answer:
Structural-functional theory
Step-by-step explanation:
The statement, "Gender division of labor exists in modern societies because it is efficient and useful to have different-but-complementary male and female roles," most closely reflects structural-functional theory.
Structural-functional theory asserts that society is complex system whose parts work together to promote solidarity and stability. It studies social structures and functions and suggests that humans are guided by these relatively stable social structures. Gender division of labor exists in modern societies because it is efficient and useful to have different-but-complementary male and female roles is a close example of structural-functional theory.