Final answer:
Anthropologists have proposed theories A, B, and E.
Step-by-step explanation:
Theories A, B, and E have been proposed by anthropologists. The long dependency period of human children requiring marriage to ensure that fathers help care for children has been proposed by anthropologists. Marriage exists because it ensures an efficient division of labor between men and women, and anthropologists have proposed that marriage exists in order to ensure that males will help protect mother and her offspring and obtain food.