We have that there are 8 participants and 4 prizes, in this problem, it's important the order of the prizes too.
Now, for the first time, there are 8 possibilities for awarding the winner prize.
For the second moment, there are just 7 possibilities for awarding the first runner-up.
Then, we have that there are 6 possibilities for awarding the second runner-up.
And, finally, we have 5 possibilities for awarding the third runner-up.
So, we have that all the ways are represented as:
[tex]8\ast7\ast6\ast5=1680[/tex]And since the order of the 4 prizes is important to get a specific prize, we have:
[tex]\frac{1680}{4!}=70[/tex]Then the correct answer would be 70.