Here is your answer
[tex]A. 130 degrees[/tex]
REASON:
We know that the angles subtended by a pair of tangents(drawn from same external point to a circle) subtend [tex]<b>supplementary angles</b>[/tex] at the centre and between them.
So,
/_XYZ + m(arcXZ ) = 180
50 + m(arcXZ)= 180
m(arcXZ)= 180-50
m(arcXZ)= 130 degrees
HOPE IT IS USEFUL
