The demand for a good becomes more inelastic a. the longer the time horizon. b. as the market is defined more broadly. c. as more close substitutes for it become available. d. as it is increasingly viewed as a luxury good.

Option D

Explanation:

The demand of a goods is said to be inelastic when there are no close substitute for it I. e when there is no competition for the goods, this rules out option C.

For the demand of a good to be considered inelastic that means people buy it regardless of the change in price, such good is since as a luxury and can't be replaced pending the time a competitor comes into play.

So there fore option D best explains when the demand of a good is inelastic.

c. as more close substitutes for it become available

Explanation:

According to the concept of elasticity of demand, the demand for a good is elastic when the percentage change in quantity demanded is equal to the percentage change in price, and it is Inelastic when a change in price of a good has a relatively small effect on the quantity of the good demanded, Inelastic demand is when the buyer's demand does not change as much as the price changes, this mostly applies to our everyday household products, essential goods are generally inelastic because consumers still demand for it even if the price changes. For example When price increases by 30% and demand decreases by 2%, demand is said to be inelastic, that is to say that the increase in price does not really affectet the demand for the goods.

So therefore, the demand for a good becomes more inelastic as more close substitutes for it become available.