An inscribed quadrilateral is any four sided figure whose vertices all lie on a circle. ... This conjecture give a relation between the opposite angles of such a quadrilateral. It says that these opposite angles are in fact supplements for each other. In other words, the sum of their measures is 180 degrees.
Option D is the correct answer. When comparing two congruent triangles, you can look at the order of the letters to see which ones are congruent. In this case, YES = NOT YE = NO since both YE and NO are the first two letters.