Answer
$$\color{blue}{\bf\text{A, C, D, E}}$$
Work Step by Step
If a ramp $\bf{\text{rises }2.5ft}$ over a $\bf{\text{run of }10 ft}$, our slope is:
$\bf{\frac{\text{rise}}{\text{run}}}$=$\bf{\frac{2.5}{10}}$
Let's look at each option to see which equal $\bf{\frac{2.5}{10}}$:
$\bf{\text{A: }0.25}$
$2.5\div10=0.25$ so $\bf{\text{A is true }}$
$\bf{\text{B: }4}$
$4=\frac{4}{1}\ne\frac{2.5}{10}$ so $\bf{\text{B is false }}$
$\bf{\text{Reality check:}}$ A slope of $\bf4$ would be $\bf{\text{very}}$ steep, far too steep for a wheelchair. (see graph)
$\bf{\text{C: }\frac{2.5}{10}}$
Which is the $\frac{\text{rise}}{\text{run}}$ form we already found so $\bf{\text{C is true }}$
$\bf{\text{D: 25%}}$
${\text{25% = }0.25}$ so $\bf{\text{D is true}}$
$\bf{\text{E: }\frac{1}{4}}$
$\frac{1}{4}=0.25$ so $\bf{\text{E is true }}$
$\bf{\text{F: }\frac{10}{2.5}}$
$\bf\frac{10}{2.5}$ would represent a $\bf{\text{rise}}$ of $\bf10\text{ft}$ over a $\bf{\text{run}}$ of $\bf2.5\text{ft}$
Which is a slope of $\bf4$ so $\bf{\text{F is false }}$
$\bf{\text{G: 400%}}$
$\bf{\text{400%}=\frac{400}{100}=4}$ so $\bf{\text{G is false }}$
$\bf{\text{H: 2.5%}}$
$\bf{\text{2.5%}=\frac{2.5}{100}=\frac{1}{40}}$so $\bf{\text{H is false }}$
$\bf{\text{Reality check:}}$ A slope of $\bf\frac{1}{40}$ would be $\bf{\text{very}}$ shallow, so it would have to be extremely long for a wheelchair ramp. (see graph)
So the correct options are:
$$\color{blue}{\bf\text{A, C, D, E}}$$