If angle 2 = angle 4 and angle 2 = 110, then by substitution, we can say that angle 4 = 110. That's b. angle 3 and 4 are supplementary angles so they add up to equal 180, therefore, c is "definition of supplementary". If angle 3 + 110 = 180, in order to solve for angle 3 we have to subtract 110 from both sides, or add the negative. So e is "addition property of equality". I'm not sure what your choices are when it says "choose an item" but that's the best I can do from what I know.
