You are correct. The answer is choice C.
The other choices A, B, D have each side add up to 180 degrees either because the angles are a linear pair (adjacent and supplementary) or because the angles are same side interior angles. Same side interior angles are supplementary if a transversal line cuts through a pair of parallel lines as so happens in this diagram.
It would be: 180/135 * 100 = 36/27 * 100
= 4/3 * 100
= 400/3 = 133.33
It means, 180 is 133.33% of 135. So, the difference would be: 133.33 - 100 = 33.33%
In short, Your Final Answer would be 33.33%
Hope this helps!