Remember one thing here, you can't divide a number by zero (0).
So in quotient function f / g, we get the the value of x that will make g zero and exclude that in set of real numbers. That will be our domain.
𝑔(𝑥) = |𝑥 + 7| ≠ 0
x ≠ -7
That means the domain is set of real numbers except -7. The answer is letter D.