The correct answer is C. 3.
The elasticity of demand is a measure of how responsive consumers are to changes in price. It is calculated by dividing the percentage change in quantity demanded by the percentage change in price. In this case, the percentage change in quantity demanded is 30%, and the percentage change in price is 10%. Therefore, the elasticity of demand is 3.
A value of 3 means that for every 1% decrease in price, the quantity demanded will increase by 3%. This is considered to be a relatively elastic demand.
A value of 1 means that for every 1% decrease in price, the quantity demanded will increase by 1%. This is considered to be a unit elastic demand.
A value of less than 1 means that for every 1% decrease in price, the quantity demanded will increase by less than 1%. This is considered to be an inelastic demand.
In this case, the elasticity of demand is 3, which means that the demand for the product is relatively elastic. This means that consumers are very responsive to changes in price, and a small decrease in price will lead to a large increase in quantity demanded.