The answer is C. 155
First find the measure of arc YZ.
The arc of WYZ is equal 180 degrees. So first add 25 to 85. Then subtract that to 180.
25+85=110
180-110=70.
Next add 70 to 85 since you want to find the measure of ZX.
70+85=155
So measure of ZX is equal to 155 degrees
