The total rate at which power is used by humans worldwide is approximately 15 TW (terawatts). The solar flux averaged over the sunlit half of Earth is 680(W)/(m(2)) (assuming no clouds). What is the area?
a. 22,058,823 km²
b. 25,000,000 km²
c. 27,941,176 km²
d. 30,882,353 km²