In order to calculate the measure of angle XYZ, we can use the following property of secant lines to a circle:
[tex]\begin{gathered} XYZ=\frac{1}{2}(XZ-ST) \\ \text{XYZ}=\frac{1}{2}(114-36) \\ \text{XYZ}=\frac{1}{2}\cdot78 \\ \text{XYZ}=39\degree \end{gathered}[/tex]
So the correct option is B.
