Answer: Option 'D' is correct.
Step-by-step explanation:
Since we have given that
[tex]f(x)=4x-6\\[/tex]
We need to find the double derivative i.e. f''(x).
So, we first derivate the f(x) w.r.t. x:
[tex]f(x)=4x-6\\\\f'(x)=4[/tex]
Now, we again derivative the f'(x) w.r.t x :
[tex]f''(x)=0[/tex]
(Because f'(x) has no term with variable x)
Hence, Option 'D' is correct.