Which of the following is a factor that would influence behavior internally?

B is the correct answer because it represents an internal psychological factor that can significantly influence an individual's behavior. Greed is a personal motivator that arises from an individual's desires, values, and priorities, leading them to act in ways that may benefit themselves financially or materially, often without regard for societal norms or laws.

In contrast, the other options reflect external influences. Department policies represent institutional guidelines that dictate acceptable behavior within a law enforcement setting. Friends can influence a person's behavior through social dynamics and peer pressures, often affecting decisions and actions based on group norms or expectations. Public perception involves the way society views law enforcement and can impact officers' actions based on community expectations and reputational considerations, but it does not stem from an individual's internal motivations or desires.