<Li> the more complex Palermo Technical Impact Hazard Scale </Li> <P> The annual background frequency used in the Palermo scale for impacts of energy greater than E megatonnes is estimated as: </P> <Dl> <Dd> f B = 0.03 E − 0.8 (\ displaystyle f_ (B) = 0.03 E ^ (- 0.8) \;) </Dd> </Dl> <Dd> f B = 0.03 E − 0.8 (\ displaystyle f_ (B) = 0.03 E ^ (- 0.8) \;) </Dd>

Which of the following is located at the center of the earth