The correct answer is D. a-1, b-2, c-3.
A normal demand curve is a downward-sloping curve that shows the relationship between the price of a good and the quantity demanded of that good. The income consumption curve is a curve that shows the relationship between income and the quantity demanded of a good. An inelastic demand curve is a curve that is relatively unresponsive to changes in price.
A normal demand curve is a downward-sloping curve that shows the relationship between the price of a good and the quantity demanded of that good. This means that, as the price of a good decreases, consumers will demand more of that good. Conversely, as the price of a good increases, consumers will demand less of that good.
The income consumption curve is a curve that shows the relationship between income and the quantity demanded of a good. This means that, as income increases, consumers will demand more of most goods. This is because, as people have more money, they can afford to buy more goods.
An inelastic demand curve is a curve that is relatively unresponsive to changes in price. This means that, even if the price of a good changes significantly, the quantity demanded of that good will not change very much. This can happen for a number of reasons, such as if the good is a necessity or if there are few substitutes available.
In conclusion, the correct answer is D. a-1, b-2, c-3.