The correct answer is C. Conflicts. Erik Erikson, a renowned developmental psychologist, proposed a psychosocial theory which outlines eight stages of human development from infancy to old age. Each stage is characterized by a unique psychosocial conflict, which refers to the challenges individuals face as they progress through different life stages. These conflicts arise from the interaction between a person's psychological needs and societal demands. Erikson believed that successfully resolving these conflicts contributes to healthy personality development and overall well-being.