To shift the function \( f(x) = x + 6 \) 4 units to the right, you need to replace \( x \) with \( x - 4 \) in the function.
So the equation becomes:
\[ g(x) = (x - 4) + 6 \] \[ g(x) = x - 4 + 6 \] \[ g(x) = x + 2 \]
Thus, the correct answer is:
g(x) = x + 2.