Quadrilateral OPQR is inscribed in circle N, as shown below. Which of the following could be used to calculate the measure of ∠PQR? (6 points) Circle N is shown with a quadrilateral OPQR inscribed inside it. Angle O is labeled x plus 16. Angle P is not labeled. Angle Q Select one: a. (6x − 4)° + (2x + 16)° = 180° b. (x + 16)° + (6x − 4)° = 180° c. (6x − 4)° + (2x + 16)° = 360° d. (x + 16)° + (6x − 4)° = 360°