The graph of the function $f(x)=-4^x$ can be obtained from the graph of $g(x)=4^x$ by one of the following actions:
(a) shifting the graph of $g(x)$ to the right 4 units;
(b) shifting the graph of $g(x)$ to the left 4 units;
(c) shifting the graph of $g(x)$ upward 4 units;
(d) shifting the graph of $g(x)$ downward 4 units;
(e) reflecting the graph of $g(x)$ in the $x$-axis;
(f) reflecting the graph of $g(x)$ in the $y$-axis;
Your answer is (input a, b, c, d, e, or f)
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 $(-\infty,A)$,
the value of $A$ is