A function f is defined on the set of real numbers as
$$f ( x ) = 1 + e ^ { - x }$$
Accordingly,\\
I. The range of function f is $( 1 , \infty )$.\\
II. Function f is decreasing on its domain.\\
III. The line $y = 0$ is a horizontal asymptote of function f.\\
Which of the following statements are true?\\
A) Only II\\
B) Only III\\
C) I and II