What is defined as an organized and relatively unchanging combination of a person's knowledge and feelings about someone or something?

The correct answer is attitude, which refers to a person's organized and enduring set of beliefs, feelings, and behaviors toward an object, person, or situation. Attitudes shape how an individual thinks and acts, providing a lens through which they interpret experiences and interactions. They often influence decision-making and behavior in various contexts, including social and professional environments.

In contrast, belief refers more specifically to the acceptance that something is true or exists, often without immediate evidence. Opinion is generally more about a person's view or judgment on specific subjects, which can change more easily than attitudes. Perception involves how a person interprets and understands sensory information; it is more about the cognitive process than the stable combination of knowledge and feelings that characterizes attitude. Thus, attitude is the best fit for describing the combination of knowledge and feelings in a relatively unchanging manner.