The correct answer is: C. An inferior good.
An inferior good is a good whose demand decreases as income increases. This is because as people’s incomes increase, they tend to substitute away from inferior goods and towards more luxurious goods.
A demand curve that is regressive at the lower end means that the demand for a good decreases as the price of the good decreases. This is a characteristic of inferior goods, as people tend to buy less of an inferior good when it becomes cheaper.
A normal good is a good whose demand increases as income increases. This is because as people’s incomes increase, they can afford to buy more of all goods, including normal goods.
A good commonly demanded is a good that is in high demand by a large number of people. This can be due to a number of factors, such as the good being essential, being seen as a status symbol, or simply being enjoyable.
A good demanded urgently is a good that is needed immediately. This can be due to the good being essential, such as food or water, or due to the good being needed for a specific purpose, such as a tool or a piece of clothing.