Answer
A
Work Step by Step
Recall: $\tan\theta=\frac{\text{side opposite}}{\text{side adjacent}}$
Given: $x=5\tan 38^{\circ}$
$\implies \tan 38^{\circ}=\frac{x}{5}$
This implies that the opposite side to the $38^{\circ}$ angle is $x$ and the adjacent side is the side with length $5$. This is the case in the right triangle A.
