Concept:An ostentatious good is bought as a status symbol, so its demand falls when its price falls.
Explanation:The price of commodity
Z falls, but the consumer chooses to purchase less of it.
This behaviour is the opposite of the law of demand, which expects quantity demanded to rise when price falls.
Goods of ostentation, such as luxury cars, designer clothes, or expensive jewellery, are valued because they are highly priced and signal wealth or status.
When the price of such a good falls, it becomes affordable to many people and loses its exclusive, prestige-giving image.
As a result, the consumer reduces his or her demand for commodity
Z.
Therefore, commodity
Z behaves like an ostentatious good, not a necessity or a normal good.
Answer:B. good of ostentation