Answer:
B
Step-by-step explanation:
[tex]1)\cos\ Q = \frac{PQ}{QR} = \frac{\sqrt{7}}{5}[/tex]
[tex]2)\ PQ = 2XY, PQR\ and\ XYZ\ - similar\ =>\ RQ = 2YZ\ and\ PR = 2XZ[/tex]
[tex]3)\ Sin\ Z = \frac{XY}{YZ} = \frac{\frac{PQ}{2}}{\frac{QR}{2}} = \frac{PQ}{QR} = \frac{\sqrt{7}}{5}[/tex]
[tex]Answer: \ \frac{\sqrt{7}}{5}[/tex]
