Final answer:
Saul's charges for parts and labor as an auto mechanic are a form of earned income, which is compensation for services rendered as opposed to passive or investment income.
Step-by-step explanation:
Saul is an auto mechanic and charges for parts and labor, which is an example of earned income. Earned income refers to money received from performing work or providing services. Since Saul is actively working to repair vehicles and charging for both the parts supplied and the labor involved, the money he makes falls into this category. Earned income typically includes wages, salaries, tips, professional fees, and other amounts received as pay for work you perform. This contrasts with passive income, which might include earnings from rental property or investments, where the earner is not actively involved in producing that income.