In July 2008, the average price of gasoline in the United States was $4.09 per gallon and consumers bought 6 percent less gasoline than they had during July 2007, when the average price was $2.96 per gallon. Based on these numbers, what was the price elasticity of demand for gasoline from July 2007 to july 2008
A) -0.16
B) -0.26
C) -3.86
D) -6.33