6. Several measurements are taken in a concert hall with electronic equipment. The data recorded by five different meters are shown below. Which meter recorded the greatest intensity level?
a) Meter 1: Area = 1 cm$^2$, 2 x 10$^{-8}$ joules measured in 1 second
b) Meter 2: Area = 1 cm$^2$, 3 x 10$^{-8}$ joules measured in 2 seconds
c) Meter 3: Area = 2 cm$^2$, 4 x 10$^{-8}$ joules measured in 2 seconds
d) Meter 4: Area = 3 cm$^2$, 3 x 10$^{-8}$ joules measured in 2 seconds
e) Meter 5: Area = 4 cm$^2$, 6 x 10$^{-8}$ joules measured in 1 second