Answer:
∠ABC = 80°
A is correct.
Step-by-step explanation:
If the measure of arc AC is 160°.
Angle subtended on circle is half the angle subtended at center on same arc.
Please refer the attachment for figure.
Therefore, \(\angle ABC = \dfrac{1}{2}arc(AC)\)
where, arc AC = 160°
\(\angle ABC = \dfrac{1}{2}\times 160^\circ\)
\(\angle ABC = 80^\circ\)
Hence, the measure of ∠ABC is 80°
