Answer
$f(x)=4x+1$
Work Step by Step
A function with $f^{\prime}(x)=4$ (for all x)
has form $f(x)=4x+c$,
where c is some constant.
The point $(0,1)$ is on the graph, so
$f(0)=1$
Since $f(0)=4(0)+c$,
it follows that $c=1$ and
$f(x)=4x+1$