Answer
D.
Work Step by Step
We can see that the equation $h=\frac{2A}{b}$ is not equivalent to (D), $h=\frac{\frac{1}{2}A}{b}$:
$\frac{2A}{b}\stackrel{?}{=}\frac{\frac{1}{2}A}{b}$
Multiply by $b$:
$b(\frac{2A}{b})\stackrel{?}{=}b(\frac{\frac{1}{2}A}{b})$
$2A\stackrel{?}{=}\frac{1}{2}A$
Divide by A:
$(2A)/A\stackrel{?}{=}(\frac{1}{2}A)/A$
$2\stackrel{?}{=}\frac{1}{2}$
$2\ne \frac{1}{2}$
This is clearly false, so the equation is not equivalent to D.
