Answer:
The correct option is C.
Explanation:
According to the central angle theorem, the angle inscribed on the circle is half of its central angle.




The measure of angle AOC is 170°.
The length of arc BC is 64°, so ∠BOC=64°.
The sum of all central angle is 360°.





The measure of angle AOB is 126°. Therefore the value of Z is 126 and option C is correct.