Final answer:
Carl mows his neighbor's yard for monetary compensation, which classifies as extrinsic motivation, a form of motivation driven by external rewards.
Step-by-step explanation:
The question posed by the student revolves around the concept of motivation, which is a psychological term referring to the reasons behind people's actions, desires, and needs. In the context provided, Carl mows his elderly neighbor's yard each week and receives $20 for his service. The type of motivation involved here is extrinsic motivation because it involves a behavior that is driven by external rewards such as money. The financial incentive operates as an external reward that prompts Carl to perform the task.