Hey there! I'm happy to help!
What we need to do is take the value of k(x) which is 3x-4 and plug it into the function h(x).
This is because our x in the function h[k(x)] is k(x), so we will substitute that value for x in that formula and that will give us our answer.
H[(k(x)]=1/(3x-4+2)
And combine like terms
H[(k(x)]=1/(3x-2)
So, our answer is C. 1/(3x-2)
Have a wonderful day and keep on learning! :D