Since the diagram represents parallel lines cut by a transversal line, the angles formed by these lines follow a series of rules. One of them is that corresponding angles are equal. Corresponding angles can be identified because they are located in the same position on different "crosses" formed by lines. In this case, angle x and the angle labeled 83° are corresponding angles and are therefore equal. We then know that angle x is 83° so choice B is correct.
I hope this helps.
