Answer:
B
Step-by-step explanation:
If we understand 2 properties of isosceles trapezoids, then we can solve for x and y easily.
First, the two sides, "2x-13" and "x-3" are equal, as shown also by red line.
So, we equate them and find x first. Shown below:

Now, another property is:
Any lower base angle is supplementary to any upper base angle. That means the angle y is supplementary to "3y-4". Supplementary means that if we add up the two angles, it will be 180 degrees. So:

From the answer choices, answer choice B is right