Answer
B
Work Step by Step
$x=5\cot 38^{\circ}\implies \cot 38^{\circ}=\frac{x}{5}$
But $\cot\theta=\frac{\text{adjacent side}}{\text{hypotenuse}}$
This implies that $x$ is the length of the adjacent side to the $38^{\circ}$ angle and the length of the side opposite to it is 5. This is the case in triangle B.
