The answer would be the 3rd one, 10 to the power of 16 (10^16).
This is because you multiply the 2 powers (2 and 8) to get 16. When there is one power within a set of parenthesis and one power on the outside the parenthesis. Since there is a 10 to the 0 power (10^0) you add this power to 16 since it is multiplying integers with exponents. Thus getting 10^16 as an answer.
