Given the following from the question?
If arc mAB = 30˚
arc mCD = 110˚
We are asked to find angle E.
to get angle E, you subtract arc mAB form arc mCD and you multiply by half
angle E = 1/2(DC - AB)
angle E = 1/2(110 - 30)
angle E = 1/2(80)
angle E = 40˚
Therefore, the correct option is C, which is 40˚.