Answer:
Option 2: 
Step-by-step explanation:
We can see that XYZ is forming right angled triangle in the given figure
where XY is Perpendicular.
XZ is Base.
YZ is Hypotenuse .
Length of XY is 3 units (refer figure)
Length of XZ is 8 units (refer figure)
Now to calculate length of ZY we will use Pythagoras theorem i.e.

By applying this theorem :


⇒
Thus Option 2 is the correct expression to determine length of ZY i.e.