we know that
In the right triangle XYZ
[tex]tan (YZX)=\frac{opposite\ side\ angle\ YZX}{adjacent\ side\ angle\ YZX}[/tex]
in this problem
[tex]opposite\ side\ angle\ YZX=XY=12.4\ cm\\adjacent\ side\ angle\ YZX=YZ=15.1\ cm[/tex]
substitute the values
[tex]tan (YZX)=\frac{12.4}{15.1}[/tex]
[tex]Angle (YZX)=arc\ tan (12.4/15.1)[/tex]
[tex]Angle (YZX)=39.4\°[/tex]
therefore
the answer is the option
B .39.4°