Ten years ago (2009), a typical solar panel could be expected to produce around 150 watts of rated power. Today, that same area of solar panel can be expected to produce around 325 watts of rated power. Based on this data, the growth rate of power generated from the same area of solar panels appears to be about

a) 2.5%

b) 4.0%

c) 8.0%

d) 15.0%