Answer:
C. 20
Step-by-step explanation:
By the property of intersecting secants outside of the circle.
[tex]x \degree = \frac{1}{2} (100 \degree - 60 \degree) \\ \\ x \degree = \frac{1}{2} \times 40 \degree \\ \\ \ x \degree = 20 \degree \\ \\ \huge \red{ \boxed{ x = 20}}[/tex]
