Final answer:
Income mobility refers to the movement of households across different income quintiles, (option C) affecting their economic status and social class with possible upward or downward movement.
Step-by-step explanation:
Income mobility refers to the movement over time of households from one income quintile to another. This involves measuring income distribution by quintiles, which ranks all households by income, then divides them into five groups with equal numbers of people. Households can experience either upward mobility or downward mobility, influencing their economic status and social class. Upward mobility is often celebrated, as in the cases of celebrities who rise from poverty to wealth, while downward mobility can occur due to setbacks such as illness, unemployment, or divorce.