The correct answer is C. Negative.
Inferior goods are goods whose demand decreases as income increases. This is because as people have more money, they tend to buy more of luxury goods and less of inferior goods.
For example, if you are poor, you might buy a lot of ramen noodles. But as you get richer, you might start to buy more expensive meals at restaurants. In this case, ramen noodles are an inferior good for you.
The income elasticity of demand is a measure of how much the demand for a good changes in response to a change in income. It is calculated by dividing the percentage change in the quantity demanded by the percentage change in income.
For an inferior good, the income elasticity of demand is negative. This means that the demand for an inferior good decreases when income increases.
Here is a table that shows the income elasticity of demand for different types of goods:
| Type of good | Income elasticity of demand |
| — | — |
| Normal good | Positive |
| Inferior good | Negative |
| Luxury good | Positive and greater than 1 |
| Necessity good | Positive and less than 1 |
I hope this helps!