Find the value of x.

The correct option is A

2 cm

We can see that, $△ABC\sim △AED$ by AAA Similarity Criterion

$\Rightarrow \frac{BC}{ED}=\frac{AC}{AD}$

$\Rightarrow \frac{8}{x}=\frac{12}{3}$

$\Rightarrow 12\times x=3\times 8$

Thus, x = 2 cm