If 3s is an even integer, the even integer that comes just before 3s is 3s-2, and the even integer that comes just after 3s is 3s+2.
The product of the integers:
[tex]3s(3s-2)(3s+2)= \\
3s ((3s)^2-2^2)= \\
3s(9s^2-4)= \\
27s^3-12s[/tex]
The answer is C.