Which of the following examples describes a social reinforcer?

A social reinforcer refers to a specific type of reinforcement that typically involves social interactions or approval from others, which can strengthen a person's behavior. Time alone—while often considered a form of avoidance or withdrawal—can involve elements of social reinforcement in certain contexts. For instance, if someone completes a task and as a result is allowed to spend time alone, this act may reinforce the behavior of completing tasks, especially if the individual values that time away from social interaction.

In the context of behavior analysis, social reinforcers often manifest as verbal praise, attention, or expressions of approval from peers or authority figures. While the other options like stickers, basketball, and chocolate can serve as tangible or material rewards, they do not inherently involve the social aspect that characterizes social reinforcers. Social reinforcers affect motivation and behavior by leveraging interpersonal dynamics and affirmations rather than physical rewards.