The parent function of g(x) = x + 9 is the function f(x) = x.
The function f(x) = x is a linear function, that is, it has degree 1 (the higher exponent of the variable x is 1).
In order to get g(x) from f(x), we can see that the function value was increased by 9 units:
[tex]g(x)=f(x)+9[/tex]
Adding 9 units to the function means we have a translation of 9 units up.
Therefore the correct option is the third one.
Graphing g(x), we have:
