Answer:
I guess, A is the wanted answer, but
A and D together are the really correct answer.
Step-by-step explanation:
if I understand this correctly, then
g(x) = sqrt(x - 3)
the domain of a function is the definition of all valid x (input) values.
the range of a function is the definition of all valid y (result) values.
well, the content (the arguments) of a square root cannot be negative (at least not while dealing with real numbers).
so, the answer options B and D are automatically out, because the domain contains values that would make the arguments of the square root negative.
I guess your teacher wants to focus only on the positive results of the square root, so A is the correct number.
BUT formally, without designated restrictions, a square root has always 2 solutions : a positive and a negative one.
because (-x)² = (x)² = x².
so, I would have to say that the really correct answer is
A + D, because the range contains both, the positive and the negative numbers.