You are comparing 10^8 and 10^4. To solve this, instead of simplifying each, note the base. They are both 10's (note that this only works if the base are the same number or variable). Subtract the variables.
10^(8 - 4) = 10^4
Note that 10^4 = 10000
D) 10,000 times greater is your answer
hope this helps
