Hi! I believe your answer is the first choice, 9.15 × [tex]10^{18}[/tex] because to find scientific notation, you need to write the non-zero digits (which is 915) placing a decimal after the first non-zero digit (which is 9.15). Then, you count the number of digits you need to move the beginning decimal to get to where your decimal is now (which is 18). If you move the decimal to the left, then your power is positive (and this number is). So, write it like this: 9.15 times 10 and how many you had to move the decimal (9.15 × [tex]10^{18}[/tex]) the 18 is positive because the original number is positive. I hope this helps you! Good luck and have a great day. :)
