When Marissa imitates her mother, carefully wrapping and setting out presents for the holiday celebration, she is praised and given holiday cookies. Marissa's learning of gender-linked behaviors is best explained by:

One day you learn that this same wealthy friend has become active in a community organization that serves the mentally challenged and their parents. you are told that her work with mentally challenged children consumes most of her weekends and a substantial part of her income and that she lives in modest circumstances. you find this hard to believe, and you suspect that somehow she is profiting from her involvement.