The graph of the function $f(x)=e^{-x}-4$ can be obtained from the graph of $g(x)=e^x$ by one of the following actions:
(a) reflecting the graph of $g(x)$ in the $x$-axis;
(b) reflecting the graph of $g(x)$ in the $y$-axis;
your answer is (input a or b)
then, by one of the following actions:
(a) shifting the resulting graph to the right 4 units;
(b) shifting the resulting graph to the left 4 units;
(c) shifting the resulting graph upward 4 units;
(d) shifting the resulting graph downward 4 units;
Your answer is (input a, b, c, or d)
Is the domain of the function $f(x)$ still $(-\infty,\infty)$?
Your answer is (input Yes or No)
The range of the function $f(x)$ is $(A,\infty)$,
the value of $A$ is