The correct answer is: A. a-2, b-4, c-1, d-3
A normal demand curve is a downwards-sloping curve that shows the relationship between the price of a good and the quantity demanded of that good, all other things being equal. An 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. The cross elasticity of demand between two perfect substitutes is infinite.
Here is a brief explanation of each option:
- A normal demand curve is a downwards-sloping curve that shows the relationship between the price of a good and the quantity demanded of that good, all other things being equal. 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.
- An 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 some goods and less of other goods. The goods that consumers demand more of as income increases are called normal goods. The goods that consumers demand less of as income increases are called inferior goods.
- An inelastic demand curve is a curve that is relatively unresponsive to changes in price. This means that, as the price of a good changes, the quantity demanded of that good changes very little. Inelastic demand curves are often seen for goods that are essential, such as food and water.
- The cross elasticity of demand between two perfect substitutes is infinite. This means that, if the price of one perfect substitute increases, the quantity demanded of the other perfect substitute will increase by an infinite amount. Perfect substitutes are goods that are identical in all respects, except for price.
I hope this helps!