First we need to find the volume of the prism without the dilated factor:
The volume would be:
Volume of the prism(without dilated) = (area of the base) * (height)
Since,
Area of base = 5

Height of the prism = 10f
Volume(without dilated) = 5*10 = 50

Now let us apply the dilated factor! For that you need to multiply for factor with the volume of the prism without dilation.
Volume of the dilated prism =

* (Volume of the prism without dilation)
Where d = dilated factor. Therefore,

v = 86.4

So the correct answer:
86.4