Final answer:
Gender roles refer to societal expectations of behavior and attributes based on biological sex, exemplified by the traditional views of masculinity and femininity in the United States. option b.
Step-by-step explanation:
In the United States, the expectations that males demonstrate aggressiveness and toughness, whereas females are expected to be passive and nurturing, illustrate the concept of gender roles. Gender roles are the social and cultural expectations imposed on individuals based on their biological sex. These roles dictate how individuals should behave, dress, and even the professions they may pursue. From infancy, socialization begins with assigning colors like blue for boys and pink for girls, extending to adulthood with 'occupational sorting,' where certain jobs are dominated by one gender over the other. However, it's important to distinguish gender roles from gender identity, which is a person's internal sense of their own gender, regardless of the roles they may perform.