The exponential function g(x) is shown on the graph. Suppose f(x) = x. Which statement is true when comparing the domain of f(x) to the domain of g(x)?
A) The domain for both functions is all positive numbers.
B) The domain for both functions is all integers.
C) The domain for both functions is all real numbers.
D) The domain for both functions is all real numbers greater than 0.