Suppose that when the price of beer is $2 per bottle, firms can sell 4 million bottles. When the price of beer is $3 per bottle, firms can sell 2 million bottles. Which of the following statements is true?_________.
选项：

A:The demand for beer is price elastic, and so an increase in the price of beer will decrease the total revenue of beer producers
B:The demand for beer is price inelastic, and so an increase in the price of beer will increase the total revenue of beer producers
C:The demand for beer is income inelastic, and so an increase in the price of beer will increase the total revenue of beer producers
D:The demand for beer is income elastic, and so an increase in the price of beer will increase the total revenue of beer producers