Final answer:
The theory that focuses on how Aiden should prefer certain colors based on his gender is the Social learning theory, which explains gender socialization through observation, imitation, and reinforcement.
Step-by-step explanation:
The question "Aiden loves to wear the color pink, but his friends say that pink is only for girls. The theory of gender development that focuses on which color of clothing Aiden should prefer based on his gender is" refers to various theories of gender development. The correct answer to this question is c) Social learning theory. This theory posits that individuals learn to exhibit certain behaviors — including preferences for color in relation to gender — through observing and imitating others, as well as through receiving positive or negative reinforcement from peers, parents, and society at large. This is a clear example of a sociological approach to understanding gender socialization, where societal expectations such as appropriate colors for boys or girls influence individual preferences and behaviors.