The angle ABC is an inscribed angle in a circle.
So, you can use the theorem that says that the measure of an inscribed angle in a circle is half the central angle.
So, the central angle is twice 46°, that is 2 * 46° = 92°.
And you also need to know that the measure of the arc is the same measure of the central angle. So the arc AC measures 92°.
Answer: 92°