Answer: Choice A
The reason why is because x = -2 leads to the denominator x+2 being zero. It's not possible to have 0 in the denominator (aka you can't divide by zero). The answer is not choice D as other x values are excluded from the domain instead of just x = -2. Recall that negative numbers aren't allowed under the square root so the domain of choice D would be x > -2 as you'd solve x+2 > 0 for x.