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, [tex]\angle ABC = \dfrac{1}{2}arc(AC)[/tex]
where, arc AC = 160°
[tex]\angle ABC = \dfrac{1}{2}\times 160^\circ[/tex]
[tex]\angle ABC = 80^\circ[/tex]
Hence, the measure of ∠ABC is 80°
