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