The correct answer is: A. Increase
Inelastic demand is a situation in which the quantity demanded of a good or service is relatively unresponsive to changes in price. This means that when the price of a good or service increases, consumers are not very likely to reduce their consumption of that good or service. As a result, the total expenditure of consumers on that good or service will increase.
For example, if the demand for gasoline is inelastic, then when the price of gasoline increases, consumers will not reduce their consumption of gasoline very much. As a result, the total amount of money that consumers spend on gasoline will increase.
On the other hand, if the demand for a good or service is elastic, then the quantity demanded of that good or service will be more responsive to changes in price. This means that when the price of a good or service increases, consumers will reduce their consumption of that good or service more significantly. As a result, the total expenditure of consumers on that good or service will decrease.
For example, if the demand for movie tickets is elastic, then when the price of movie tickets increases, consumers will reduce their consumption of movie tickets more significantly. As a result, the total amount of money that consumers spend on movie tickets will decrease.
In conclusion, if the demand of a commodity is inelastic, an increase in its price will cause the total expenditure of the consumers of the goods to increase.