How do you solve for domain and range?

Find the domain and range of the real-valued function f (x) = x2 + 7. B) The domain is all real numbers x such that x ≥ 0 and the range is all real numbers f (x) such that f (x) ≥ 7. C) The domain is all real numbers x such that x ≥ 0 and the range is all real numbers.