Final answer:
If a good is normal, income and demand for the good are positively related, which means that as income increases, so does the demand for the normal good.
Step-by-step explanation:
If a good is normal, then the correct answer is: c. income and demand for the good are positively related. This relationship means that as a person's income increases, their demand for the normal good also increases. This is because a normal good has a positive income elasticity of demand.
For instance, products like luxury cars, vacations, or fine jewelry see greater demand when consumers have higher incomes. Conversely, an inferior good would see a decrease in demand as income rises since people would then be able to afford more expensive choices.