Answer:
An increase in your income causes you to buy more hamburgers.
Step-by-step explanation:
An increase in your income causes you to buy more hamburgers.
Option "A" is correct because the increase in income exhibits an increase in purchasing power. Moreover, there is a positive relationship between the income the demand for normal goods which means if the income rises, then the demand rises. If the income falls, then demand for goods also falls. Therefore, option "a" is right.